Wireless communication between wideband enb and narrowband ue

ABSTRACT

A method and apparatus for wireless communication in the unlicensed spectrum between an eNB and UEs having different bandwidths, e.g., between a narrowband UE and a wideband eNB. A base station apparatus performs an LBT procedure at a beginning of frames and transmits a plurality of repetitions of a transmission. When the plurality of repetitions span multiple frames and the LBT procedure is not successful for a first frame, the base station drops or postpones at least one repetition in the first frame until a second frame when the LBT procedure is successful. A UE receives the plurality of repetitions and may combine a plurality of repetitions across multiple frames. The UE may determine whether the base station drops the at least one repetition in the first frame or postpones the at least one repetition in the first frame until a second frame.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser.No. 62/416,651, entitled “WIRELESS COMMUNICATION BETWEEN WIDEBAND ENBAND NARROWBAND UE” and filed on Nov. 2, 2016, which is expresslyincorporated by reference herein in its entirety.

BACKGROUND Field

The present disclosure relates generally to communication systems, andmore particularly, to wireless communication between a base station andUser Equipment (UE) having different bandwidths, e.g., between awideband base station and a narrowband UE.

Background

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources. Examples of suchmultiple-access technologies include code division multiple access(CDMA) systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example telecommunication standardis Long Term Evolution (LTE). LTE is a set of enhancements to theUniversal Mobile Telecommunications System (UMTS) mobile standardpromulgated by Third Generation Partnership Project (3GPP). LTE isdesigned to support mobile broadband access through improved spectralefficiency, lowered costs, and improved services using OFDMA on thedownlink, SC-FDMA on the uplink, and multiple-input multiple-output(MIMO) antenna technology. However, as the demand for mobile broadbandaccess continues to increase, there exists a need for furtherimprovements in LTE technology. These improvements may also beapplicable to other multi-access technologies and the telecommunicationstandards that employ these technologies.

By way of example, a wireless multiple-access communication system mayinclude a number of base stations, each simultaneously supportingcommunication for multiple communication devices, otherwise known asuser equipment (UEs). A base station may communicate with UEs ondownlink channels (e.g., for transmissions from a base station to a UE)and uplink channels (e.g., for transmissions from a UE to a basestation).

Some modes of communication may enable communications between a basestation and a UE over a contention-based shared radio frequency spectrumband, or over different radio frequency spectrum bands (e.g., a licensedradio frequency spectrum band or an unlicensed radio frequency spectrumband) of a cellular network. With increasing data traffic in cellularnetworks that use a licensed radio frequency spectrum band, offloadingof at least some data traffic to an unlicensed radio frequency spectrumband may provide a cellular operator with opportunities for enhanceddata transmission capacity. An unlicensed radio frequency spectrum bandmay also provide service in areas where access to a licensed radiofrequency spectrum band is unavailable.

In Narrow Band (NB) wireless communication, such as narrow bandinternet-of-things (NB-IoT) or enhanced Machine-Type Communications(eMTC), wireless communications may involve limited bandwidth. Forexample, in NB-IoT, wireless communication may be limited to a singleResource Block (RB). In eMTC, communication may be limited to six RBs.Such limited resources lead to unique challenges in transmitting data.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

Aspects presented herein provide the ability use an unlicensed or sharedradio frequency spectrum band, providing opportunities for enhanced datatransmission capacity, and also addresses the unique challenges intransmitting narrow band wireless communication. Aspects provide forcommunication between a base station and UEs having different bandwidthsin the unlicensed spectrum, e.g., between a wideband base station andnarrow band UEs. The communication may comprise Internet of Things (IoT)communication, e.g., NB-IoT, eMTC, etc. By enabling wideband basestations to serve narrow band UEs using the unlicensed spectrum, largernumbers of UEs may be served by fewer base stations.

In an aspect of the disclosure, a method, a computer-readable medium,and an apparatus for wireless communication at an base station areprovided. The apparatus performs a dual CCA procedure for a frame,wherein the dual CCA procedure comprises a first type of CCA procedurefollowed by a second type of CCA procedure when the first type of CCAprocedure is unsuccessful. The apparatus may transmit during the framewhen at least one CCA procedure of the dual CCA procedure is successfuland may refrain from transmitting during the frame when both CCAprocedures of the dual CCA procedure are unsuccessful. In performing thedual CCA procedure, the apparatus may perform CCA for a first period oftime then perform eCCA for a second period of time following the CCA,when the CCA is unsuccessful.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus for wireless communication at user equipmentare provided. The apparatus segments an uplink duration in each frameinto multiple transmission units for each frequency, wherein a framecomprises an integer number of the transmission units. The apparatusthen transmits uplink communication based on the multiple transmissionunits, wherein each transmission unit comprises at least one on periodand at least one off period corresponding to each of a plurality offrequencies, wherein during an on period the UE transmits uplinkcommunication on the corresponding frequency and during an off periodthe UE refrains from transmitting uplink communication on thecorresponding frequency.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus for wireless communication at a user equipmentis provided. The apparatus transmits uplink transmissions in a pluralityof transmission units and hops frequency bands in a first pattern acrossframes based on a base station hopping pattern. The uplink transmissionsmay be transmitted based on dual hopping patterns, and the apparatus mayfurther hop in a second pattern across transmission units within thebase station's channel occupancy within a frame.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus for wireless communication at a base stationare provided. The apparatus hops frequency bands in a first patternacross frames based on a base station hopping pattern and receivesuplink transmissions in a narrowband from a user equipment in aplurality of transmission units within the frequency bands based on thebase station hopping pattern. The uplink transmission may be receivedfrom the user equipment based on dual hopping patterns, and theapparatus may hop in a second pattern across transmission units withinthe base station's channel occupancy within a frame. The uplinktransmission may be received from the user equipment in the samenarrowband within the corresponding channel occupancy of the basestation in each frame. The base station may comprise a wideband basestation, and the apparatus may further multiplex communication with aplurality of narrowband UEs.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus for wireless communication at a base stationare provided. The apparatus performs a Listen-Before-Talk (LBT)procedure at a beginning of each of a plurality of frames. The apparatustransmits a plurality of repetitions of a transmission, wherein when theplurality of repetitions span multiple frames and the LBT procedure isnot successful for a first frame, the base station drops at least onerepetition in the first frame or postpones the at least one repetitionin the first frame until a second frame when the LBT procedure issuccessful.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus for wireless communication at a user equipmentare provided. The apparatus receives a plurality of repetitions of adownlink transmission from a base station. When the plurality ofrepetitions span multiple frames, the apparatus determines whether thebase station transmits at least one repetition of the downlinktransmission in a first frame. The determining may include determiningwhether the base station drops the at least one repetition in the firstframe or postpones the at least one repetition in the first frame untila second frame. The apparatus may combine the plurality of repetitionsacross the multiple frames.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagram that illustrates an example of a wirelesscommunications system according to various aspects of the presentdisclosure.

FIG. 2A shows a diagram that illustrates examples of deploymentscenarios for using LTE in an unlicensed spectrum according to variousaspects of the present disclosure.

FIG. 2B shows a diagram that illustrates another example of a deploymentscenario for using LTE in an unlicensed spectrum according to variousaspects of the present disclosure.

FIG. 3 shows a diagram that illustrates an example of carrieraggregation when using LTE concurrently in licensed and unlicensedspectrum according to various aspects of the present disclosure.

FIG. 4 shows an example of a CCA procedure performed by a transmittingapparatus when contending for access to a contention-based shared radiofrequency spectrum band, in accordance with various aspects of thepresent disclosure.

FIG. 5 shows an example of an eCCA procedure performed by a transmittingapparatus when contending for access to a contention-based shared radiofrequency spectrum band, in accordance with various aspects of thepresent disclosure.

FIG. 6 shows a block diagram of a design of a base station/evolved NodeB (eNB) and a UE, which may be one of the base stations/eNBs and one ofthe UEs in FIG. 1.

FIG. 7 illustrates an example frame structure in accordance with aspectspresented herein.

FIG. 8 illustrates an example CCA/eCCA structure in accordance withaspects presented herein.

FIG. 9 illustrates an example frame structure in accordance with aspectspresented herein.

FIG. 10 illustrates an example transmission unit structure in accordancewith aspects presented herein.

FIG. 11 illustrates an example frame structure in accordance withaspects presented herein.

FIG. 12 is a flowchart of a method of wireless communication at a basestation.

FIG. 13 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an example apparatus.

FIG. 14 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 15 is a flowchart of a method of wireless communication at a userequipment.

FIG. 16 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an example apparatus.

FIG. 17 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 18 is a flowchart of a method of wireless communication at a userequipment.

FIG. 19 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an example apparatus.

FIG. 20 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 21 is a flowchart of a method of wireless communication at a basestation.

FIG. 22 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an example apparatus.

FIG. 23 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 24 is a flowchart of a method of wireless communication at a basestation.

FIG. 25 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an example apparatus.

FIG. 26 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 27 is a flowchart of a method of wireless communication at a userequipment.

FIG. 28 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an example apparatus.

FIG. 29 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to limit the scope of the disclosure.Rather, the detailed description includes specific details for thepurpose of providing a thorough understanding of the inventive subjectmatter. It will be apparent to those skilled in the art that thesespecific details are not required in every case and that, in someinstances, well-known structures and components are shown in blockdiagram form for clarity of presentation.

Techniques are described in which an unlicensed radio frequency spectrumband is used for at least a portion of contention-based communicationsover a wireless communication system. In some examples, acontention-based shared radio frequency spectrum band may be used forLTE communications or LTE-Advanced (LTE-A) communications. Thecontention-based radio frequency spectrum band may be used incombination with, or independent from, a non-contention licensed radiofrequency spectrum band. In some examples, the contention-based radiofrequency spectrum band may be a radio frequency spectrum band for whicha device may also need to contend for access because the radio frequencyspectrum band is available, at least in part, for unlicensed use, suchas Wi-Fi use.

With increasing data traffic in cellular networks that use a licensedradio frequency spectrum band, offloading of at least some data trafficto a contention-based shared radio frequency spectrum band, such as inan unlicensed band, may provide a cellular operator (e.g., an operatorof a public land mobile network (PLMN) or a coordinated set of basestations defining a cellular network, such as an LTE/LTE-A network) withopportunities for enhanced data transmission capacity. As noted above,before communicating over a contention-based shared radio frequencyspectrum band, such as unlicensed spectrum, devices may perform an LBTprocedure to gain access to the shared radio frequency spectrum band.Such an LBT procedure may include performing a CCA procedure (or an eCCAprocedure) to determine whether a channel of the unlicensed radiofrequency spectrum band is available. When it is determined that thechannel of the contention-based radio frequency spectrum band isavailable, a channel reserving signal (e.g., a CUBS) may be transmittedto reserve the channel. When it is determined that a channel is notavailable, a CCA procedure (or eCCA procedure) may be performed for thechannel again at a later time.

When a base station and/or a UE includes multiple antenna ports capableof transmitting over the contention-based shared radio frequencyspectrum band, transmissions from different antenna ports may interferewith one another due to correlation between transmitted signals. For achannel reserving signal used to reserve a channel of a contention-basedshared radio frequency spectrum band, reduction of interference due tocorrelation between transmitted signals may be important to provide gooddetection capabilities for reserving the channel, and to prevent falsedetection that would unnecessarily reserve the channel and prevent otherdevices from using the channel. To reduce such interference due tocross-correlation of signals from different antennas or auto-correlationof a signal from a single antenna, the base station or the UE maygenerate a sequence based at least in part on an antenna port identifierassociated with an antenna port that transmits the sequence of thechannel reserving signal. In this way, correlation of channel reservingsignals may be reduced, thereby improving detection capabilities of thesignal transmission, resulting in more effective and accuratereservations of a channel of the contention-based shared radio frequencyspectrum band.

In other words, for a channel reserving signal used to reserve a channelof an unlicensed radio frequency spectrum band, the channel reservingsignal should be configured with good detectability to reduce falsealarms, so that the channel reservation may be easily detected by otherdevices trying to access the shared radio frequency spectrum band. Thus,the channel reserving signal sequence should have good auto-correlationproperties and good cross-correlation properties with sequences fromneighbor base stations. For example, a primary synchronization signal(PSS), a secondary synchronization signal (SSS), and/or a channel stateinformation-reference signal (CSI-RS) may not have good auto-correlationproperties or good cross-correlation properties between different basestations in the contention-based shared radio frequency spectrum band.Thus, the channel reserving signal sequence should be configured basedat least in part on an antenna port identifier to provide goodauto-correlation and cross-correlation properties.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in other examples.

FIG. 1 is an illustration of an example wireless communication system100, in accordance with various aspects of the present disclosure. Thewireless communication system 100 may include base stations 105, UEs115, and a core network 130. The core network 130 may provide userauthentication, access authorization, tracking, Internet Protocol (IP)connectivity, and other access, routing, or mobility functions. The basestations 105 may interface with the core network 130 through backhaullinks 132 (e.g., S1, etc.) and may perform radio configuration andscheduling for communication with the UEs 115, or may operate under thecontrol of a base station controller (not shown). In various examples,the base stations 105 may communicate, either directly or indirectly(e.g., through core network 130), with other base stations 105 overbackhaul links 134 (e.g., X2, etc.), which may be wired or wirelesscommunication links.

The base stations 105 may wirelessly communicate with the UEs 115 viaone or more base station antennas. Each of the base station 105 sitesmay provide communication coverage for a respective geographic coveragearea 110. In some examples, a base station 105 may be referred to as abase transceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNB, a Home NodeB, a Home eNB, or some othersuitable terminology. The geographic coverage area 110 for a basestation 105 may be divided into sectors making up a portion of thecoverage area (not shown). The wireless communication system 100 mayinclude base stations 105 of different types (e.g., macro or small cellbase stations). There may be overlapping geographic coverage areas 110for different technologies.

In some examples, the wireless communication system 100 may include anLTE/LTE-A network. In LTE/LTE-A networks, the term eNB may be used todescribe the base stations 105, while the term UE may be used todescribe the UEs 115. The wireless communication system 100 may be aHeterogeneous LTE/LTE-A network in which different types of eNBs providecoverage for various geographical regions. For example, each eNB or basestation 105 may provide communication coverage for a macro cell, a smallcell, or other types of cell. The term “cell” is a 3GPP term that can beused to describe a base station, a carrier or component carrierassociated with a base station, or a coverage area (e.g., sector, etc.)of a carrier or base station, depending on context.

A macro cell may cover a relatively large geographic area (e.g., severalkilometers in radius) and may allow unrestricted access by UEs withservice subscriptions with the network provider. A small cell may be alower-powered base station, as compared with a macro cell that mayoperate in the same or different (e.g., licensed, unlicensed, etc.)radio frequency spectrum bands as macro cells. Small cells may includepico cells, femto cells, and micro cells according to various examples.A pico cell may cover a relatively smaller geographic area and may allowunrestricted access by UEs with service subscriptions with the networkprovider. A femto cell also may cover a relatively small geographic area(e.g., a home) and may provide restricted access by UEs having anassociation with the femto cell (e.g., UEs in a closed subscriber group(CSG), UEs for users in the home, and the like). An eNB for a macro cellmay be referred to as a macro eNB. An eNB for a small cell may bereferred to as a small cell eNB, a pico eNB, a femto eNB or a home eNB.An eNB may support one or multiple (e.g., two, three, four, and thelike) cells (e.g., component carriers).

The wireless communication system 100 may support synchronous orasynchronous operation. For synchronous operation, the base stations mayhave similar frame timing, and transmissions from different basestations may be approximately aligned in time. For asynchronousoperation, the base stations may have different frame timing, andtransmissions from different base stations may not be aligned in time.The techniques described herein may be used for either synchronous orasynchronous operations.

The communication networks that may accommodate some of the variousdisclosed examples may be packet-based networks that operate accordingto a layered protocol stack. In the user plane, communications at thebearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based.A Radio Link Control (RLC) layer may perform packet segmentation andreassembly to communicate over logical channels. A Medium Access Control(MAC) layer may perform priority handling and multiplexing of logicalchannels into transport channels. The MAC layer may also use Hybrid ARQ(HARQ) to provide retransmission at the MAC layer to improve linkefficiency. In the control plane, the Radio Resource Control (RRC)protocol layer may provide establishment, configuration, and maintenanceof an RRC connection between a UE 115 and the base stations 105 or corenetwork 130 supporting radio bearers for the user plane data. At thePhysical (PHY) layer, the transport channels may be mapped to Physicalchannels.

The UEs 115 may be dispersed throughout the wireless communicationsystem 100, and each UE 115 may be stationary or mobile. A UE 115 mayalso include or be referred to by those skilled in the art as a mobilestation, a subscriber station, a mobile unit, a subscriber unit, awireless unit, a remote unit, a mobile device, a wireless device, awireless communications device, a remote device, a mobile subscriberstation, an access terminal, a mobile terminal, a wireless terminal, aremote terminal, a handset, a user agent, a mobile client, a client, orsome other suitable terminology. A UE 115 may be a cellular phone, apersonal digital assistant (PDA), a wireless modem, a wirelesscommunication device, a handheld device, a tablet computer, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, or thelike. A UE may be able to communicate with various types of basestations and network equipment, including macro eNBs, small cell eNBs,relay base stations, and the like.

The communication links 125 shown in wireless communication system 100may include DL transmissions, from a base station 105 to a UE 115, or ULtransmissions from a UE 115 to a base station 105. The downlinktransmissions may also be called forward link transmissions, while theuplink transmissions may also be called reverse link transmissions. Insome examples, UL transmissions may include transmissions of uplinkcontrol information, which uplink control information may be transmittedover an uplink control channel (e.g., a physical uplink control channel(PUCCH) or enhanced PUCCH (ePUCCH)). The uplink control information mayinclude, for example, acknowledgements or non-acknowledgements ofdownlink transmissions, or channel state information. Uplinktransmissions may also include transmissions of data, which data may betransmitted over a physical uplink shared channel (PUSCH) or enhancedPUSCH (ePUSCH). Uplink transmissions may also include the transmissionof a sounding reference signal (SRS) or enhanced SRS (eSRS), a physicalrandom access channel (PRACH) or enhanced PRACH (ePRACH) (e.g., in adual connectivity mode or the standalone mode described with referenceto FIGS. 2A and 2B), or an SR or enhanced SR (eSR) (e.g., in thestandalone mode described with reference to FIGS. 2A and 2B). Referencesin this disclosure to a PUCCH, a PUSCH, a PRACH, an SRS, or an SR arepresumed to inherently include references to a respective ePUCCH,ePUSCH, ePRACH, eSRS, or eSR.

In some examples, each communication link 125 may include one or morecarriers, where each carrier may be a signal made up of multiplesub-carriers (e.g., waveform signals of different frequencies) modulatedaccording to the various radio technologies described above. Eachmodulated signal may be sent on a different sub-carrier and may carrycontrol information (e.g., reference signals, control channels, etc.),overhead information, user data, etc. The communication links 125 maytransmit bidirectional communications using a frequency domain duplexing(FDD) operation (e.g., using paired spectrum resources) or a time domainduplexing (TDD) operation (e.g., using unpaired spectrum resources).Frame structures for FDD operation (e.g., frame structure type 1) andTDD operation (e.g., frame structure type 2) may be defined.

In some aspects of the wireless communication system 100, base stations105 or UEs 115 may include multiple antennas for employing antennadiversity schemes to improve communication quality and reliabilitybetween base stations 105 and UEs 115. Additionally or alternatively,base stations 105 or UEs 115 may employ multiple-input, multiple-output(MIMO) techniques that may take advantage of multi-path environments totransmit multiple spatial layers carrying the same or different codeddata.

The wireless communication system 100 may support operation on multiplecells or carriers, a feature which may be referred to as carrieraggregation (CA) or multi-carrier operation. A carrier may also bereferred to as a component carrier (CC), a layer, a channel, etc. Theterms “carrier,” “component carrier,” “cell,” and “channel” may be usedinterchangeably herein. A UE 115 may be configured with multipledownlink CCs and one or more uplink CCs for carrier aggregation. Carrieraggregation may be used with both FDD and TDD component carriers.

The wireless communication system 100 may also or alternatively supportoperation over a non-contention licensed radio frequency spectrum band(e.g., a radio frequency spectrum band for which transmittingapparatuses may not contend for access because the radio frequencyspectrum band is licensed to particular users for particular uses, suchas a licensed radio frequency spectrum band usable for LTE/LTE-Acommunications) or a contention-based shared radio frequency spectrumband (e.g., an unlicensed radio frequency spectrum band for whichtransmitting apparatuses may need to contend for access because theradio frequency spectrum band is available for unlicensed use, such asWi-Fi use). Upon winning a contention for access to the contention-basedshared radio frequency spectrum band, a transmitting apparatus (e.g., abase station 105 or UE 115) may transmit one or more channel reservingsignals (e.g., one or more CUBS) over the unlicensed radio frequencyspectrum band. The channel reserving signals may serve to reserve theunlicensed radio frequency spectrum by providing a detectable energy onthe unlicensed radio frequency spectrum band. The channel reservingsignals may also serve to identify a transmitting apparatus and/or atransmitting antenna, or may serve to synchronize the transmittingapparatus and a receiving apparatus. In some examples, a channelreserving signal transmission may commence at a symbol period boundary(e.g., an OFDM symbol period boundary). In other examples, a CUBStransmission may commence between symbol period boundaries.

The number and arrangement of components shown in FIG. 1 are provided asan example. In practice, wireless communication system 100 may includeadditional devices, fewer devices, different devices, or differentlyarranged devices than those shown in FIG. 1. Additionally, oralternatively, a set of devices (e.g., one or more devices) of wirelesscommunication system 100 may perform one or more functions described asbeing performed by another set of devices of wireless communicationsystem 100.

Turning next to FIG. 2A, a diagram 200 shows examples of a supplementaldownlink mode (e.g., licensed assisted access (LAA) mode) and of acarrier aggregation mode for an LTE network that supports LTE/LTE-Aextended to contention-based shared spectrum. The diagram 200 may be anexample of portions of the system 100 of FIG. 1. Moreover, the basestation 105-a may be an example of the base stations 105 of FIG. 1,while the UEs 115-a may be examples of the UEs 115 of FIG. 1.

In the example of a supplemental downlink mode (e.g., LAA mode) indiagram 200, the base station 105-a may transmit OFDMA communicationssignals to a UE 115-a using a downlink 205. The downlink 205 isassociated with a frequency F1 in an unlicensed spectrum. The basestation 105-a may transmit OFDMA communications signals to the same UE115-a using a bidirectional link 210 and may receive SC-FDMAcommunications signals from that UE 115-a using the bidirectional link210. The bidirectional link 210 is associated with a frequency F4 in alicensed spectrum. The downlink 205 in the unlicensed spectrum and thebidirectional link 210 in the licensed spectrum may operateconcurrently. The downlink 205 may provide a downlink capacity offloadfor the base station 105-a. In some embodiments, the downlink 205 may beused for unicast services (e.g., addressed to one UE) services or formulticast services (e.g., addressed to several UEs). This scenario mayoccur with any service provider (e.g., traditional mobile networkoperator or MNO) that uses a licensed spectrum and needs to relieve someof the traffic and/or signaling congestion.

In one example of a carrier aggregation mode in diagram 200, the basestation 105-a may transmit OFDMA communications signals to a UE 115-ausing a bidirectional link 215 and may receive SC-FDMA communicationssignals from the same UE 115-a using the bidirectional link 215. Thebidirectional link 215 is associated with the frequency F1 in theunlicensed spectrum. The base station 105-a may also transmit OFDMAcommunications signals to the same UE 115-a using a bidirectional link220 and may receive SC-FDMA communications signals from the same UE115-a using the bidirectional link 220. The bidirectional link 220 isassociated with a frequency F2 in a licensed spectrum. The bidirectionallink 215 may provide a downlink and uplink capacity offload for the basestation 105-a. Like the supplemental downlink (e.g., LAA mode) describedabove, this scenario may occur with any service provider (e.g., MNO)that uses a licensed spectrum and needs to relieve some of the trafficand/or signaling congestion.

In another example of a carrier aggregation mode in diagram 200, thebase station 105-a may transmit OFDMA communications signals to a UE115-a using a bidirectional link 225 and may receive SC-FDMAcommunications signals from the same UE 115-a using the bidirectionallink 225. The bidirectional link 225 is associated with the frequency F3in an unlicensed spectrum. The base station 105-a may also transmitOFDMA communications signals to the same UE 115-a using a bidirectionallink 230 and may receive SC-FDMA communications signals from the same UE115-a using the bidirectional link 230. The bidirectional link 230 isassociated with the frequency F2 in the licensed spectrum. Thebidirectional link 225 may provide a downlink and uplink capacityoffload for the base station 105-a. This example and those providedabove are presented for illustrative purposes and there may be othersimilar modes of operation or deployment scenarios that combineLTE/LTE-A with or without contention-based shared spectrum for capacityoffload.

As described above, the typical service provider that may benefit fromthe capacity offload offered by using LTE/LTE-A extended tocontention-based spectrum is a traditional MNO with LTE spectrum. Forthese service providers, an operational configuration may include abootstrapped mode (e.g., supplemental downlink (e.g., LAA mode), carrieraggregation) that uses the LTE PCC on the non-contention spectrum andthe LTE SCC on the contention-based spectrum.

In the supplemental downlink mode, control for LTE/LTE-A extended tocontention-based spectrum may be transported over the LTE uplink (e.g.,uplink portion of the bidirectional link 210). One of the reasons toprovide downlink capacity offload is because data demand is largelydriven by downlink consumption. Moreover, in this mode, there may not bea regulatory impact since the UE is not transmitting in an unlicensedspectrum. There is no need to implement LBT or carrier sense multipleaccess (CSMA) requirements on the UE. However, LBT may be implemented onthe base station (e.g., eNB) by, for example, using a periodic (e.g.,every 10 milliseconds) CCA and/or a grab-and-relinquish mechanismaligned to a radio frame boundary.

In the CA mode, data and control may be communicated in LTE (e.g.,bidirectional links 210, 220, and 230) while data may be communicated inLTE/LTE-A extended to contention-based shared spectrum (e.g.,bidirectional links 215 and 225). The carrier aggregation mechanismssupported when using LTE/LTE-A extended to contention-based sharedspectrum may fall under a hybrid frequency division duplexing-timedivision duplexing (FDD-TDD) carrier aggregation or a TDD-TDD carrieraggregation with different symmetry across component carriers.

FIG. 2B shows a diagram 200-a that illustrates an example of astandalone mode for LTE/LTE-A extended to contention-based sharedspectrum. The diagram 200-a may be an example of portions of the system100 of FIG. 1. Moreover, the base station 105-b may be an example of thebase stations 105 of FIG. 1 and the base station 105-a of FIG. 2A, whilethe UE 115-b may be an example of the UEs 115 of FIG. 1 and the UEs115-a of FIG. 2A.

In the example of a standalone mode in diagram 200-a, the base station105-b may transmit OFDMA communications signals to the UE 115-b using abidirectional link 240 and may receive SC-FDMA communications signalsfrom the UE 115-b using the bidirectional link 240. The bidirectionallink 240 is associated with the frequency F3 in a contention-basedshared spectrum described above with reference to FIG. 2A. Thestandalone mode may be used in non-traditional wireless accessscenarios, such as in-stadium access (e.g., unicast, multicast). Anexample of the typical service provider for this mode of operation maybe a stadium owner, cable company, event hosts, hotels, enterprises, andlarge corporations that do not have licensed spectrum. For these serviceproviders, an operational configuration for the standalone mode may usethe PCC on the contention-based spectrum. Moreover, LBT may beimplemented on both the base station and the UE.

In some examples, a transmitting apparatus such as one of the basestations 105, 205, or 205-a described with reference to FIG. 1, 2A, or2B, or one of the UEs 115, 215, 215-a, 215-b, or 215-c described withreference to FIG. 1, 2A, or 2B, may use a gating interval to gain accessto a channel of a contention-based shared radio frequency spectrum band(e.g., to a physical channel of an unlicensed radio frequency spectrumband). In some examples, the gating interval may be periodic. Forexample, the periodic gating interval may be synchronized with at leastone boundary of an LTE/LTE-A radio interval. The gating interval maydefine the application of a contention-based protocol, such as an LBTprotocol based at least in part on the LBT protocol specified inEuropean Telecommunications Standards Institute (ETSI). When using agating interval that defines the application of an LBT protocol, thegating interval may indicate when a transmitting apparatus needs toperform a contention procedure (e.g., an LBT procedure) such as a clearchannel assessment (CCA) procedure. The outcome of the CCA procedure mayindicate to the transmitting apparatus whether a channel of acontention-based shared radio frequency spectrum band is available or inuse for the gating interval (also referred to as an LBT radio frame).When a CCA procedure indicates that the channel is available for acorresponding LBT radio frame (e.g., “clear” for use), the transmittingapparatus may reserve or use the channel of the contention-based sharedradio frequency spectrum band during part or all of the LBT radio frame.When the CCA procedure indicates that the channel is not available(e.g., that the channel is in use or reserved by another transmittingapparatus), the transmitting apparatus may be prevented from using thechannel during the LBT radio frame.

The number and arrangement of components shown in FIGS. 2A and 2B areprovided as an example. In practice, wireless communication system 200may include additional devices, fewer devices, different devices, ordifferently arranged devices than those shown in FIGS. 2A and 2B.

FIG. 3 is an illustration of an example 300 of a wireless communication310 over an unlicensed radio frequency spectrum band, in accordance withvarious aspects of the present disclosure. In some examples, an LBTradio frame 315 may have a duration of ten milliseconds and include anumber of downlink (D) subframes 320, a number of uplink (U) subframes325, and two types of special subframes, an S subframe 330 and an S′subframe 335. The S subframe 330 may provide a transition betweendownlink subframes 320 and uplink subframes 325, while the S′ subframe335 may provide a transition between uplink subframes 325 and downlinksubframes 320 and, in some examples, a transition between LBT radioframes.

During the S′ subframe 335, a downlink clear channel assessment (CCA)procedure 345 may be performed by one or more base stations, such as oneor more of the base stations 105, 205, or 205-a described with referenceto FIG. 1 or 2, to reserve, for a period of time, a channel of thecontention-based shared radio frequency spectrum band over which thewireless communication 310 occurs. Following a successful downlink CCAprocedure 345 by a base station, the base station may transmit apreamble, such as a CUBS (e.g., a downlink CUBS (D-CUBS 350)) to providean indication to other base stations or apparatuses (e.g., UEs, Wi-Fiaccess points, etc.) that the base station has reserved the channel. Insome examples, a D-CUBS 350 may be transmitted using a plurality ofinterleaved resource blocks. Transmitting a D-CUBS 350 in this mannermay enable the D-CUBS 350 to occupy at least a certain percentage of theavailable frequency bandwidth of the contention-based shared radiofrequency spectrum band and satisfy one or more regulatory requirements(e.g., a requirement that transmissions over an unlicensed radiofrequency spectrum band occupy at least 80% of the available frequencybandwidth). The D-CUBS 350 may in some examples take a form similar tothat of an LTE/LTE-A cell-specific reference signal (CRS) or a channelstate information reference signal (CSI-RS). When the downlink CCAprocedure 345 fails, the D-CUBS 350 may not be transmitted.

The S′ subframe 335 may include a plurality of OFDM symbol periods(e.g., 14 OFDM symbol periods). A first portion of the S′ subframe 335may be used by a number of UEs as a shortened UL (U) period 340. Asecond portion of the S′ subframe 335 may be used for the DL CCAprocedure 345. A third portion of the S′ subframe 335 may be used by oneor more base stations that successfully contend for access to thechannel of the contention-based shared radio frequency spectrum band totransmit the D-CUBS 350.

During the S subframe 330, an UL CCA procedure 365 may be performed byone or more UEs, such as one or more of the UEs 115, 215, 215-a, 215-b,or 215-c described above with reference to FIG. 1, 2A, or 2B, toreserve, for a period of time, the channel over which the wirelesscommunication 310 occurs. Following a successful UL CCA procedure 365 bya UE, the UE may transmit a preamble, such as an UL CUBS (U-CUBS 370) toprovide an indication to other UEs or apparatuses (e.g., base stations,Wi-Fi access points, etc.) that the UE has reserved the channel. In someexamples, a U-CUBS 370 may be transmitted using a plurality ofinterleaved resource blocks. Transmitting a U-CUBS 370 in this mannermay enable the U-CUBS 370 to occupy at least a certain percentage of theavailable frequency bandwidth of the contention-based radio frequencyspectrum band and satisfy one or more regulatory requirements (e.g., therequirement that transmissions over the contention-based radio frequencyspectrum band occupy at least 80% of the available frequency bandwidth).The U-CUBS 370 may in some examples take a form similar to that of anLTE/LTE-A CRS or CSI-RS. When the UL CCA procedure 365 fails, the U-CUBS370 may not be transmitted.

The S subframe 330 may include a plurality of OFDM symbol periods (e.g.,14 OFDM symbol periods). A first portion of the S subframe 330 may beused by a number of base stations as a shortened DL (D) period 355. Asecond portion of the S subframe 330 may be used as a guard period (GP)360. A third portion of the S subframe 330 may be used for the UL CCAprocedure 365. A fourth portion of the S subframe 330 may be used by oneor more UEs that successfully contend for access to the channel of thecontention-based radio frequency spectrum band as an UL pilot time slot(UpPTS) or to transmit the U-CUBS 370.

In some examples, the downlink CCA procedure 345 or the UL CCA procedure365 may include the performance of a single CCA procedure. In otherexamples, the DL CCA procedure 345 or the uplink CCA procedure 365 mayinclude the performance of an extended CCA procedure. The extended CCAprocedure may include a random number of CCA procedures, and in someexamples may include a plurality of CCA procedures.

As indicated above, FIG. 3 is provided as an example. Other examples arepossible and may differ from what was described in connection with FIG.3.

FIG. 4 is an illustration of an example 400 of a CCA procedure 415performed by a transmitting apparatus when contending for access to acontention-based shared radio frequency spectrum band, in accordancewith various aspects of the present disclosure. In some examples, theCCA procedure 415 may be an example of the DL CCA procedure 345 or ULCCA procedure 365 described with reference to FIG. 3. The CCA procedure415 may have a fixed duration. In some examples, the CCA procedure 415may be performed in accordance with an LBT-frame based equipment(LBT-FBE) protocol. Following the CCA procedure 415, a channel reservingsignal, such as a CUBS 420, may be transmitted, followed by a datatransmission (e.g., an UL transmission or a DL transmission). By way ofexample, the data transmission may have an intended duration 405 ofthree subframes and an actual duration 410 of three subframes.

As indicated above, FIG. 4 is provided as an example. Other examples arepossible and may differ from what was described in connection with FIG.4.

FIG. 5 is an illustration of an example 500 of an eCCA procedure 515performed by a transmitting apparatus when contending for access to acontention-based shared radio frequency spectrum band, in accordancewith various aspects of the present disclosure. In some examples, theeCCA procedure 515 may be an example of the DL CCA procedure 345 or ULCCA procedure 365 described with reference to FIG. 3. The eCCA procedure515 may include a random number of CCA procedures, and in some examplesmay include a plurality of CCA procedures. The eCCA procedure 515 may,therefore, have a variable duration. In some examples, the eCCAprocedure 515 may be performed in accordance with an LBT-load basedequipment (LBT-LBE) protocol. The eCCA procedure 515 may provide agreater likelihood of winning contention to access the contention-basedshared radio frequency spectrum band, but at a potential cost of ashorter data transmission. Following the eCCA procedure 515, a channelreserving signal, such as a CUBS 520, may be transmitted, followed by adata transmission. By way of example, the data transmission may have anintended duration 505 of three subframes and an actual duration 510 oftwo subframes.

As indicated above, FIG. 5 is provided as an example. Other examples arepossible and may differ from what was described in connection with FIG.5.

FIG. 6 shows a block diagram of a design of a base station 105, e.g., aneNB, and a UE 115, which may be one of the base stations/eNBs and one ofthe UEs in FIG. 1. The base station 105 may be equipped with antennas634 a through 634 t, and the UE 115 may be equipped with antennas 652 athrough 652 r. At the base station 105, a transmit processor 620 mayreceive data from a data source 612 and control information from acontroller/processor 640. The control information may be for thephysical broadcast channel (PBCH), physical control format indicatorchannel (PCFICH), physical hybrid automatic repeat request indicatorchannel (PHICH), physical downlink control channel (PDCCH), etc. Thedata may be for the physical downlink shared channel (PDSCH), etc. Thetransmit processor 620 may process (e.g., encode and symbol map) thedata and control information to obtain data symbols and control symbols,respectively. The transmit processor 620 may also generate referencesymbols, e.g., for the primary synchronization signal (PSS), secondarysynchronization signal (SSS), and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 630 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODs) 632 a through 632t. Each modulator 632 may process a respective output symbol stream(e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator632 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal.Downlink signals from modulators 632 a through 632 t may be transmittedvia the antennas 634 a through 634 t, respectively.

At the UE 115, the antennas 652 a through 652 r may receive the downlinksignals from the base station 105 and may provide received signals tothe demodulators (DEMODs) 654 a through 654 r, respectively. Eachdemodulator 654 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 654 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 656 may obtainreceived symbols from all the demodulators 654 a through 654 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 658 may process (e.g., demodulate,deinterleave, and decode) the detected symbols, provide decoded data forthe UE 115 to a data sink 660, and provide decoded control informationto a controller/processor 680.

On the uplink, at the UE 115, a transmit processor 664 may receive andprocess data (e.g., for the PUSCH) from a data source 662 and controlinformation (e.g., for the PUCCH) from the controller/processor 680. Thetransmit processor 664 may also generate reference symbols for areference signal. The symbols from the transmit processor 664 may beprecoded by a TX MIMO processor 666 if applicable, further processed bythe demodulators 654 a through 654 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 105. At the base station 105, the uplinksignals from the UE 115 may be received by the antennas 634, processedby the modulators 632, detected by a MIMO detector 636 if applicable,and further processed by a receive processor 638 to obtain decoded dataand control information sent by the UE 115. The processor 638 mayprovide the decoded data to a data sink 646 and the decoded controlinformation to the controller/processor 640.

The controllers/processors 640 and 680 may direct the operation at thebase station 105 and the UE 115, respectively. The controller/processor640 and/or other processors and components at the base station 105 mayperform or direct the execution of various processes for the techniquesdescribed herein. The controllers/processor 680 and/or other processorsand components at the UE 115 may also perform or direct the execution ofthe functional blocks illustrated in FIGS. 12-17, and 20-22, and/orother processes for the techniques described herein. The memories 642and 682 may store data and program codes for the base station 105 andthe UE 115, respectively. A scheduler 644 may schedule UEs for datatransmission on the downlink and/or uplink.

A device, such as a UE, may have multiple antennas (N) to use forreceiving and/or transmitting signals. The device may divide the use andassignment of the antennas to use for particular radio accesstechnologies (RATs), such as LTE, Wi-Fi, etc., for particular carrierfrequencies, or both. For example, the device may use a fixed number ofantennas for one carrier in CA cases, or it may use a fixed number ofantennas for Wi-Fi when the device supports both Wi-Fi and othertechnologies, such as LTE. In one example, a UE may have four antennasand assign two of the antennas for Wi-Fi communication and two antennasfor LTE communications. A device, such as a UE, may also dynamically orsemi-statically select a number of antennas for one technology or onecarrier (antenna selection). In such dynamic or semi-static schemes, thesharing or selection may be triggered by a particular measurementresult, such as channel quality indicator (CQI), reference signalreceive power (RSRP), and the like.

Communications networks, such as LTE, may have frequency divisionmultiplexing (FDM) implementations and time division multiplexing (TDM)implementations. Sharing options in FDM implementations are not trulysharing different antennas, but rather sharing the frequency spectrumreceived over the antenna. For example, a UE may use a diplexer/switchin order to use all antennas at the same time for differentair-interfaces. The diplexer/switch acts as a filter by filtering outthe unwanted frequencies. However, in such FDM sharing schemes, there istypically a considerable loss in signal strength as the signals arefiltered. Such losses can also increase with the higher frequency bands.TDM implementations may actually use or assign separate antennas foreach air-interface/technology. Thus, when communications over suchair-interfaces/technologies are not in use, those antennas that wereassigned or designated for the unused communications may be shared withother air-interfaces/technologies. The various aspects of the presentdisclosure are directed to communication systems using TDMimplementations.

NB wireless communication involves unique challenges due to the limitedfrequency dimension of the narrow band. One example of such NB wirelesscommunication is NB-IoT, which is limited to a single RB of systembandwidth, e.g., 180 kHz. Another example of NB wireless communicationis eMTC, which is limited to six RBs of system bandwidth. The NBcommunication may be deployed in a “standalone” system, e.g., in adedicated spectrum. Multiple users may utilize the narrow band. Whileonly some of the UEs may be active at a particular time, the NBcommunication should support such multi-user capacity.

Additionally, NB communication may need to provide for deep coverage, byaccounting for devices in environments requiring different CoverageEnhancement (CE) levels. For example, some devices may need as much as20 dB of CE, which results in greater uplink Transmission Time Interval(TTI) bundling, further limiting time resources.

NB-IoT communication may also involve a large cell radius, e.g., as muchas approximately 35 km. Thus, the communication may involve a longdelay, such as 200 μs, which may employ a long Cyclic Prefix (CP)length.

Similar challenges are involved with NB communication using eMTC, e.g.,with Category 0, low cost MTC UEs. An MTC UE may be implemented withreduced peak data rates (e.g., a maximum of 1000 bits for a transportblock size). Further, an MTC UE may be limited to supporting rank 1transmissions and/or having 1 receive antenna. When an MTC UE ishalf-duplex, the MTC UE may have a relaxed switching timing (switchingfrom transmission to reception or reception to transmission) compared tolegacy or non-MTC UEs in accordance with the LTE standards. For example,a non-MTC UE may have a switching time on the order of 20 microseconds,while an MTC UE may have a switching time on the order of 1 millisecond.

MTC UEs may monitor DL control channels in the same way as non-MTC UEs,e.g., monitoring wideband signals, monitoring for both PDCCH and EPDCCH,etc. Additional MTC enhancements may be supported. Although MTC UEsoperate in a narrowband, the MTC UEs may also be capable of operation ina wider system bandwidth (e.g., 1.4/3/5/10/15/20 MHz). For example, theMTC UEs may work in a system bandwidth of 1.4 MHz and may use 6 resourceblocks (RBs). Further, the MTC UEs may have enhanced coverage up to 15dB.

In eMTC with extended coverage support, one or more channels may bebundled (e.g., repeated) in the time domain. In particular, bundledM-PDCCH may use multiple subframes for transmission. Resources for anM-PDCCH may be allocated by an eNB in accordance with requirements forePDCCH within the narrowband on which an MTC UE is operating.

Aspects presented herein provide for wireless communication between basestation and UEs having different bandwidths. The communication maycomprise IoT communication, e.g., NB-IoT, eMTC, etc. The aspects mayenable such wireless communication between base stations and UEs havingdifferent bandwidths while operating in the unlicensed or sharedspectrum.

There are a number of regulations regarding wireless communication inthe unlicensed spectrum. These regulations may vary by country.

For example, in the United States, there may be regulations regardingthe frequency for unlicensed wireless communication, e.g., between2400-2483.5 MHz. Digital modulation for such unlicensed wirelesscommunication may include bandwidth limitations, transmission powerlimitations, etc. For example, wireless communication on the unlicensedspectrum may be subject to a 500 KHz minimum bandwidth, 30 dBm ofmaximum transmission power, 36 dBm maximum Effective Isotropic RadiatedPower (EIRP), a maximum transmit Power Spectral Density (PSD) of 8 dBm/3KHz. For digital modulation operation, there may be no dwell timelimits.

There may also be additional regulations regarding frequency hoppingoperation. For example, in the United States, frequency hopping in theunlicensed spectrum is allowed for hopping channels having a maximum of25 kHz and 20 dB bandwidth. In one example, when output power is lessthan or equal to 21 dBm, the maximum may be 25 kHz and ⅔*20 dBbandwidth. The hopping may be required to comprise a pseudo randomlydetermined frequency and uniform occupancy for each channel over onefull hopping cycle. Thus, while a pattern may be used, the pattern maybe required to be pseudo random. Receivers may have input bandwidthsthat match the hopping channel bandwidths of transmitters and may shiftfrequencies in synchronization with the transmitted channels. Thestructure or regulations may vary depending on the number of channelsused for frequency hopping. For example, for frequency hopping using atleast 15 channels, the maximum dwell time may be 0.4 seconds. This mayavoid transmissions on a certain channel provided that a minimum of 15channels are used for the frequency hopping. If at least 75 channels areused, then the maximum transmission power may be 30 dBm. If less than 75channels are used, the maximum transmission power may be 21 dBm.Intelligent hopping may be performed, e.g., allowing the avoidance ofsome channels per device. However, coordination among multiple devicesmay not be allowed.

A hybrid system may employ a combination of both frequency hopping anddigital modulation techniques. Such a hybrid system may comprise amaximum transmit Power Spectral Density (PSD) of 8 dBm/3 KHz. As well,the frequency hopping operation of the hybrid system may have a dwelltime limit of 0.4 seconds per channel. Thus, the occupancy on anyfrequency may be regulated to not exceed 0.4 seconds. The number ofhopping channels might not be limited.

In Europe, there are regulations for non adaptive frequency hopping andfor adaptive frequency hopping.

For non-adaptive frequency hopping, there is a maximum transmissionpower of 20 dBm and a 100 kHz minimum hopping bandwidth. For example,Medium Utilization (MU) may be limited to less than 10% where MU=(P/100mW)*DC. P is a transmission power. DC is a duty cycle, which may bedeclared by the manufacturer based on observations over maximum dwellperiods.

In Europe, there may be a 5 ms maximum on time and a requirement for atleast a 5 ms gap between transmissions.

There may also be a 15 ms dwell time on a given frequency in 15*N ms. Ina first option, each hopping frequency in the hop set may be occupied atleast one in a period of 4 N*dwell time. In a second option, theoccupation probability of each frequency may be limited to between 25%of 1/N and 77% of 1/N. N is a number of hopping frequencies used.

An occupied channel bandwidth may be regulated to contain 99% of thepower of the transmission. If the EIRP is more than 10 dBm, then anominal channel bandwidth may be less than or equal to 5 MHz.

Equipment may transmit on at least one hopping frequency while otherhopping frequencies are blacklisted. Blacklisted frequencies areconsidered as active for computing MU. Equipment may be required tooccupy that frequency for the duration of the dwell time.

For adaptive frequency hopping, there may be a 20 dBm maximum transmitpower, a 0.4 s dwell time within 0.4 s*N, where N is greater thanmax(15, 15BW (MHz)). A 100 kHz minimum hopping bandwidth may operateover 70% of the band. MU may be the same as for non-adaptive frequencyhopping. A minimum frequency occupation may be 1 dwell time (DWT) withina period not exceeding 4*DWT*N. The transmission may be on at least twofrequencies.

At least one of two Detect And Avoid (DAA) methods may be employed.Listen Before Transmit (LBT) is one example of a DAA method. For LBTbased DAA, a CCA may be based on a 0.2% observation period at the startof a dwell time with a minimum of 20 μs. When a signal is above anEnergy Detect (ED) level, then the frequency may be skipped and is notcounted toward the 15 channel requirement. If the channel is notskipped, then, the device may wait without transmitting. As anotheroption, the device may perform eCCA with 1 to 5% of a channel occupancytime. The channel occupancy time may be 60 ms followed by an idle periodof a maximum (5%, 100 μs), which means 5% of channel occupancy time(e.g., 3 ms for 60 ms) or 100 μs, whichever is the largest. When usingLBT based DAA, if a signal is detected, a jump may be made to the nextfrequency in the hopping sequence provided the time for a maximum dwelltime is respected.

Another DAA method may involve evaluating channels for signal presenceand avoiding those frequencies for a maximum of (1 sec, 5*N*COT) whenthe channel is found to be busy, where COT is a channel occupancy time.A maximum COT may be 40 ms, and an idle period may have a maximum of (5%of COT, 100 μs) after a COT.

For wideband modulation, there may be a 20 dBm maximum transmissionpower, a maximum transmit PSD of 10 dBm/MHz, and a maximum bandwidth of20 MHz. A transmission sequence may be less than 10 ms with a minimumtransmission gap=max(upcoming transmission sequence, 3.5 ms). MU may besimilar to the unlicensed spectrum. (MU) may be limited to less than 10%where MU=(P/100 mW)*DC. LBT and non LBT DAA may be employed.

Other countries may have different regulations regarding wirelesscommunication in the unlicensed spectrum.

Base Station and UE with Different Bandwidths

Aspects presented herein enable wireless communication in the unlicensedspectrum between a base station and a UE having different bandwidths.Table 1 illustrates a table of examples of possible bandwidthcombinations between eNBs and UEs in the unlicensed spectrum.

TABLE 1 eNB bandwidth UE bandwidth (MHz) (MHz) Comments 1.4, 5, 10, 201.4 Adaptation of eMTC design 10, 20 5 Wideband UE capability 5 5Coverage extension based on MF 1.0 FS3 10 10 design (UL waveform may bedifferent) 20 20

In one example, the base station may be a wideband eNB, or other basestation, capable of wideband communication, and the UE may be a NB UE.For example the UE may have a bandwidth of 1.08 MHz. The eNB may be basestation 105, 105-a, 105-b and the UE may be UE 115, 115-a, 115-b.

The eNB may perform a LBT operation before transmitting, while the UEmay transmit to the eNB without performing an LBT operation. FIGS. 4 and5 illustrate example aspects of example LBT operations. FIG. 7illustrates an example frame structure 700 for communication between awideband eNB and a NB UE. As illustrated, at the start of each frame,the eNB may perform an LBT 702. The eNB may then transmit for theduration of the frame. The duration of the LBT portion 702 of the frame,the Uplink (UL) portion 706 of the frame, and the downlink (DL) portion704 of the frame may be configurable by the eNB.

A 20 MHz eNB may be deployed using a digital modulation mode or a hybridmode. An eNB of up to 5 MHz may be deployed using a frequency hoppingmode. Thus, in one example, the eNB may have a 5 MHz bandwidth and theUE may have a 1.4 MHz bandwidth.

In one example, the frame structure 700 of FIG. 7 may have a duration of40 ms. In this example, up to 10 frames may be transmitted on eachhopping frequency, e.g., for a maximum dwell period of 400 ms on afrequency. The number of the frames may be a function of the bandwidthsupported by the eNB, e.g., as the number of narrow bands in a givenbandwidth over which the UE hops is a function of the eNB bandwidth.

As the duration of the LBT 702, DL portion 704, and UL portion 706 maybe configured by the eNB, for the 40 ms frame, the DL duration may be 8ms, the UL duration may be 30 ms, and the LBT duration may be 2 ms forUL heavy communication. For DL heavy communication, the DL duration maybe 28 ms, the UL duration may be 10 ms, and the LBT duration may be 2ms.

An idle period of 5% may be important, e.g., to satisfy regulatoryrequirements. In order to achieve this idle period, the UL duration 706of the frame may be applied toward the idle period. Thus, when there are2 UL subframes in a frame duration, the idle period for the eNB may bemet.

The initial CCA requirements for the LBT operation at 702 may have anobservation period of at least 40 ms*0.002. In the example of a 40 msframe, the CCA observation period may be 80 μs. However, in anotherexample, at least 200 μs channel observation period may be used to covera 2 symbol retuning gap used in eMTC applications by UEs.

The LBT procedure may comprise performing CCA or eCCA, as described inconnection with FIGS. 4 and 5. FIG. 8 illustrates frame structure 800having an example duration for an initial CCA 802 and an extended CCA804.

If an base station transmitted on a previous frame or if the presentframe is the first frame on a frequency, the base station may attempt aninitial CCA 802 in the first 200 μs of the frame. If the initial CCA 802is successful, the base station may transmit a reservation signal for1.8 ms and then may start frame transmission, e.g., 704, 706. If thebase station did not transmit on the previous frame on a frequency, thebase station may wait until the CCA location for the next frame boundaryand may try eCCA again.

If the initial CCA 802 fails, the base station may begin performing eCCAfor a duration between, e.g., 400 μs to 1.8 ms. If eCCA is unsuccessful,the base station may wait until the CCA location for the next frameboundary and may try eCCA again.

The total base station transmission time may be 1.8 ms/0.05=36 ms. Thus,the maximum DL duration 704 may be 36 ms, and a minimum UL duration 706may be 4 ms for each frame. The 4 ms minimum UL provides a base stationidle period.

A frame structure may be different in the first frame or in a number ofinitial frames on a given hopping frequency. For example, there may be aminimum number of subframes in each burst that can function as anchor DLsubframes that are always present when the base station wins mediumaccess via CCA/eCCA. FIG. 9 illustrates an example frame structure 900having DL portions 904 a, 904 b of different durations and UL portions906 a, 906 b of different durations. Although LBT portions 902 a, 902 bmay be configured differently for different frames, in FIG. 9, the LBTportions 90 sa, 902 b are the same. Similarly, idle periods 908 a, 908 bare illustrated as having the same duration.

Therefore, the base station has the ability to configure the DL duration904, 904 b and the UL duration 906 a, 906 b based on the information tobe communicated. For example, DL heavy frames may carry more DL and ULgrants or network signaling messages such as paging and SystemInformation Blocks (SIBs).

Concentrating base station transmissions, e.g., in DL portion 904 a, hasthe potential to reduce UE power consumption by reducing the amount oftime the UE monitors the medium. Channel estimation gains may also beachieved due to a longer transmission on a single frequency or due to atransmission without gaps.

In one example, the DL-UL ratio in each of the frames can beconfigurable on a long term basis. The DL-UL ratio may be signaled,e.g., by RRC signaling or through an indication in a SIB.

Allowed frame structures may be defined, stored in a table, etc. Thebase station may then signal the adopted frame structure to the UE. Forexample, the base station may signal the adopted frame structure to theUE using a SIB. This would enable the base station to change the framestructure after each SIB modification period.

As discussed above, the UE may transmit UL communication during ULduration, e.g., 706, 906 a, 906 b without performing an LBT. Thus, theUE may transmit to the base station when it receives a grant from thebase station, e.g., in DL duration 704, 904 a, 904 b. A base stationtransmission is detectable to all UEs common signals, e.g., PSS/SSS.However, UE transmission detection at the base station may consumesignificant amounts of overhead. By removing the requirement for the UEto perform LBT, this overhead may be reduced. Transmitting ULcommunication from the UE to the base station also reduces powerconsumption at the UE due to the simpler overall operation. Regulationsmay impose stricter constraints on transmission characteristics fortransmissions sent without LBT.

For example, European regulations may require a 5 ms on time to befollowed by a 5 ms off time. The on time is cumulative on any frequency.There may be a 15 ms maximum dwell time on any given frequency in 4*15*Nms, where N is a number of the hopping frequencies.

Therefore, the UE may use a frame structure that comprises atransmission unit having a 5 ms on period and a 5 ms off period. Thisenables a UE to meet regulatory compliance by design. This modularstructure of transmission units allows changes when off periods are notneeded in a region. FIG. 10 illustrates an example UL transmission unit1000 having a first portion comprising a 5 ms ON period 1002 followed bya second portion comprising a 5 ms OFF period 1004. The UL duration,e.g., 706, 906 a, 906 b may be divided into multiple transmission units1000. Each frame may comprise 1, 2, or 3 UL transmission units 1000,e.g., 10 ms, 20 ms, or 30 ms of UL transmissions depending on theconfiguration selected by the base station, or based on a specification.This can simplify the signaling aspects and the UE procedures as aninteger number of UL transmission units may be contained in a frame. Inorder to efficiently use the capacity of the wideband base station,different UEs may be multiplexed in each transmission unit.

FIG. 10 illustrates an example in which the transmission unit for asecond UE (UE 2) may be configured opposite that of the first UE (UE 1).For example in the first 5 ms, the transmission unit for UE1 has an ONperiod 1002 while UE 2 has an OFF period 1006. Similarly the second 5 msof the transmission unit 1000 is an OFF period for UE 1 1004 and an ONperiod for UE 2 1008. Thus, the ON/OFF portions of transmission unitsfor different UEs may be interleaved in order to make efficient use ofthe resources at the base station.

Aspects may include UL data channel bundling for the UE. For example, asame redundancy version (RV) and scrambling sequence may be applied toDMRS and PUSCH during the 5 ms period in each transmission unit for theUE.

For UL PUSCH scheduling, when the UE needs less than 5 subframes, PUSCHmay be scheduled within one transmission unit, e.g., 1000. Asillustrated in FIG. 10, other UEs may be multiplexed on the remainingresources, e.g., during OFF period 1004, etc. When the UE needs morethan 5 subframes for its UL transmission, the base station may schedulePUSCH for the UE in multiples of transmission units 1000. The UL startdelay may also be specified from the base station to the UE in terms oftransmission units 1000.

FIG. 11 illustrates an example frame structure 1100 for narrowband UEs(e.g., 115, 115-a, 115-b, 1350, 1902, 1902′, 2250) to hop within achannel occupancy of a wideband base station (e.g., 105, 105-a, 105-b,1950, 2202, 2202′). The frame structure 1100 includes an LBT portion1102 at the beginning of the frame during which the base station mayperform CCA/eCCA. LBT portion 1102 may correspond to LBT duration 702,902 a, 902 b. The frame structure 1100 includes a DL portion 1104 and anUL portion comprising three transmission units 1106, 1108, 1110. DLportion 1104 may correspond to DL duration 704, 904 a, 904 b. The ULportion composed of transmission units 1106, 1108, 1110 may correspondto UL duration 706, 906 a, 906 b.

The frame structure 1100 comprises multiple NB channels, e.g., NB 1,NB2, NB3, NB4. As described in the present application, the base stationmay be capable of transmitting or receiving across a wider bandwidththan the UEs with which the base station communicates. For example, theUEs might each only be able to transmit or receive on a single NBchannel, whereas the base station is capable of transmission andreception across multiple NB channels.

NB UEs may use an UL frequency hopping pattern within a wideband basestation's channel occupancy. In a first example, the UE may transmit ULtransmissions to the base station using frequency hopping acrosstransmission units within a frame, as in FIG. 11. FIG. 11 illustrates anexample for a 25 RB eNB and for 5 MHz. In the example in FIG. 1, a firstUE transmits UL transmission in NB1 for transmission unit 1, in NB2 fortransmission unit 2, and in NB4 for transmission unit 4. Thus, the UEhops NB frequency channels within the base station bandwidth for thebase station's channel occupancy during the frame. After the frame, theUE may jump to a different frequency in accordance with a correspondingfrequency hop by the base station. In another example, the UE maytransmit UL transmissions to the base station using frequency hoppingacross frames with the same NB being used within each frame. Forexample, the UE may transmit a maximum of 3UL transmission units in agiven NB channel before it moves to a new NB channel.

The UE may perform two level frequency hopping among NB channels. First,the UE may hop within the base station's NB channels using a hopfrequency with a fixed pattern, e.g., similar to the hopping pattern ofFIG. 11. Second, the base station and the UE may hop across the wholeunlicensed frequency band, e.g., in accordance with any regulatoryrequirements on hopping.

A number of frames per frequency before performing the second hop inwhich the base station and the UE hop to a new frequency may be afunction of the number of DL subframes in the frame structure and thenumber of narrow bands on which the UE can hop within the base station'schannel occupancy.

A number of narrow bands may be defined for IoT, e.g., NB-IoT and/oreMTC. For example, for eMTC bandwidths 5, MHz, 10 MHz, and 20 MHzresults in 4 narrow bands, 8 narrow bands, and 16 narrow bands,respectively, over which the UE can hop within the base station'schannel occupancy. FIG. 11 illustrates 4 narrow bands on which the UEmay hop. In eMTC, only two narrow bands may be provided for allchannels, and up to 4 channels may be for PDCCH/PDSCH only.

In a first example, for a 5 MHz base station bandwidth, 4 frames perfrequency is 160 ms, which corresponds to 12 UL transmission units perhop frequency across all frames. The UE may use 3 transmission units pernarrowband for a total of 12 transmission units across the 4 frames.

In a second example, for a base station having a 10 MHz bandwidth, 8frames per frequency is 320 ms, which corresponds to 24 UL transmissionunits per hop frequency across all frames. The UE may use 3 transmissionunits per narrowband for a total of 24 transmission units across the 8frames.

A wideband base station provides higher capacity at a single basestation to serve multiple UEs at the same time. This reduces the numberof base stations that need to be deployed, and therefore, reduces thecost needed to serve a given number of users. A wideband base stationalso enables a higher dwell time per NB channel, because the UEs may hopin-band with the base station bandwidth occupancy. Through the use ofdifferent hopping patterns at different base stations allows a networkto avoid interference from transmissions in other cells. For example, Nhopping frequencies used by the base station implies that N differentbase stations within an area can coexist without any interference in acontrolled environment. The choice of N may depend on regulations or thebandwidth chosen by the base station. The choice of N may also be basedon the minimum number of frequencies that the UE needs to transmit.While different DL/UL configurations may be used for each base stationin a frame, interference may be avoided from nearby base stations usinghopping. This enables different base stations to have different DL-ULconfigurations in each frame without any mixed interference scenarios.

As illustrated in FIGS. 7. 9, and 11, DL transmissions from the basestation may each be gated with an LBT at the beginning of the frame.This may impact MPDCCH repetitions. For a small number of repetitions,the MPDCCH may be transmitted in one frame. For a larger number ofrepetitions, MPDCCH may span multiple frames, each frame having anindependent LBT. It may be simpler for the base station to transmit allthe repetitions of the DL grants within one frame. Some DL heavingframes, e.g., similar to 904 a, may be sufficient to enable this optionwithout an impact on the coverage. In a different example, when MPDCCHspans multiple frames, then the MPDCCH may either be gated by an LBT, ormay be postponed, e.g., until a next frame sent by the base station. Forboth options, the UE needs to be able to accurately determine whetherthe base station is transmitting so that it can soft-combine theinformation across frames. A postponed MPDCCH may affect other UEscheduling as UEs may only be awake during a discontinuous reception(DRX) on period.

Similarly, MPDSCH transmissions may span multiple frames. If the UEreceives a DL grant from the base station, then the base station hassimilar option to either postpone the MPDSCH transmission or to gate theMPDSCH transmission with an LBT procedure.

The selection between gating or postponing the MPDCCH or MPDSCH may bemade dynamically by the base station or may be based on a specification.For example, the base station may dynamically select whether to gate orpostpone the MPDCCH or MPDSCH based on the interference environment,based on a likelihood of the UE missing the transmission from the basestation, and/or a likelihood of the UE falsely detecting a non-existingbase station transmission. The dynamic selection may be based on howreliably the UE may detect whether the base station transmission is onor off.

In contrast, LBT may not have a major impact on UL transmissions such asMPUCCH or MPUSCH. The UE may transmit to the base station withoutperforming an LBT operation. The UE may transmit MPUCCH and MPUSCH in aframe even if the base station did not transmit during the DL subframes.For MPRACH, when resources are allocated by a cell-specificconfiguration, the UE may attempt RACH transmissions at a designatedtime, e.g., without LBT.

FIG. 12 is a flowchart 1200 of a method of wireless communication. Themethod may be performed by a base station (e.g., the base station 105,105-a, 105-b, the apparatus 1302/1302′) communicating wirelessly with aUE (e.g., UE 115, 115-a, 115-b, 1350). Optional aspects in FIG. 12 areillustrated using a dashed line. The wireless communication may compriseeMTC in an unlicensed or shared spectrum. The base station may performan LBT operation at a beginning of a frame, prior to transmittingdownlink communication to the UE, e.g., as described in connection withFIGS. 4, 5, and 8. The base station may transmits a downlinkcommunication to a UE on an unlicensed spectrum using a first bandwidthand may receive uplink communication from a UE using a second, narrowerbandwidth, e.g., as described in connection with FIGS. 7, 9, and 11.Thus, base station may communicate with a narrow band UE using a narrowband and may also be capable of communicating as a wide band basestation.

As illustrated in FIG. 12, at 1202, the base station performs a dual CCAprocedure for a frame. The dual CCA procedure at 1202 may be performedwhen the base station transmitted on a previous frame or prior to thebase station transmitting the frame as a first frame on a frequency,e.g., as described in connection with FIG. 8. The dual CCA procedure maycomprise a first type of CCA procedure followed by a second type of CCAprocedure when the first type of CCA procedure is unsuccessful. Thus, at1208, the base station may perform a first type of CCA procedure. At1210, the base station may determine whether the first type of CCAprocedure was successful. If not, at 1214, the base station may performa second type of CCA procedure.

At 1204, the base station may transmit during the frame when at leastone CCA procedure of the dual CCA procedure is successful. At 1206, thebase station may refrain from transmitting during the frame when bothCCA procedures of the dual CCA procedure are unsuccessful.

The first type of CCA procedure may comprise CCA and the second type ofCCA procedure may comprise eCCA. Thus, at 1208, the base station mayperform CCA for a first period of time and may perform eCCA for a secondperiod of time at 1212 when the CCA at 1210 is unsuccessful. The secondperiod of time, e.g., for performing eCCA, may be longer than the firstperiod of time, e.g., for performing CCA.

When CCA is determined to be successful at 1210, the base station maytransmit a reservation signal, at 1216, and may transmit a frametransmission, at 1218, following the reservation signal. Similarly, whenCCA is unsuccessful, yet eCCA is determined to be successful at 1214,the base station may transmit a reservation signal, at 1216, and maytransmit a frame transmission, at 1218, following the reservationsignal. When the eCCA is successful, the reservation signal length isbased on the time from the successful eCCA to the frame boundary. Then,the frame transmission starts. Thus, the reservation signal fills thegap between the eCCA and the frame boundary.

When neither CCA nor eCCA is successful, the base station may, at 1220,wait until a next CCA location at a next frame boundary. Then, at 1222,the base station may perform the second type of CCA procedure, e.g.,eCCA, at the next CCA location.

A first transmission time corresponding to the first type of CCAprocedure at 1208 may be independent of a first duration of the firsttype CCA and a second transmission time corresponding to the second CCAprocedure at 1212 may be based on a second duration of the second typeCCA. Thus, the transmission time for CCA may be independent of the CCAduration while for eCCA, the transmission time is a function of the eCCAduration. The eCCA duration can be smaller if the downlink transmissiontime is smaller. To align the start transmission times for differentframe structures, each of which have a different downlink duration, avariable length of reservation signal time may be applied.Alternatively, the eCCA may be started later so that the end of the eCCAcoincides with the subframe boundary where data transmission starts.

The base station may receive UL communication from the UE without an LBToperation from the UE. Thus, the frame may comprise an LBT portion,e.g., 702, 902 a, 902 b, a DL portion, e.g., 704, 904 a, 904 b; and anUL portion, e.g., 706, 906 a, 906 b. The eNB may transmit downlinkcommunication or receive uplink communication for the duration of aframe after performing the LBT operation, as illustrated in FIG. 7. TheLBT operation duration, a downlink duration, and an uplink duration ofthe frame may be configurable by the eNB. In order to configure thesedurations, the eNB may select a frame structure having a defineddownlink duration and a defined uplink duration. The eNB may then signalthe selected frame structure to the UE.

FIG. 13 is a conceptual data flow diagram 1300 illustrating the dataflow between different means/components in an example apparatus 1302.The apparatus may be a base station (e.g., e.g., the base station 105,105-a, 105-b). The apparatus includes a reception component 1304configured to receive uplink communication from at least one UE 1350,and a transmission component 1306 configured to transmit DLcommunication to the at least one UE 1350. The wireless communicationmay comprise eMTC in an unlicensed or shared spectrum.

The apparatus may include a dual CCA component 1308 configured toperform a dual clear CCA procedure for a frame, wherein the dual CCAprocedure comprises a first type of CCA procedure, e.g., CCA, followedby a second type of CCA procedure, e.g., eCCA, when the first type ofCCA procedure is unsuccessful. Thus, the dual CCA component 1308 mayinclude a CCA component 1310 and an eCCA component 1312. The apparatusmay include a CCA determination component 1314 configured to determinewhether the first type of CCA procedure and/or the second type of CCAprocedure was successful. When one of the types of CCA procedures wassuccessful, the CCA determination component 1314 may be configured toindicate to a transmission component (e.g., any of 1306, 1316, or 1318)to transmit during the frame. When both CCA procedures of the dual CCAprocedure are unsuccessful the CCA determination component 1314 mayindicate to refrain from transmitting during the frame. The apparatusmay include a reservation component 1316 configured to transmit areservation signal when one of the CCA procedures is successful and aframe transmission component 1318 configured to transmit a frametransmission following the reservation signal. When both CCA and eCCAare unsuccessful, the CCA determination component may configured tocause the apparatus to wait until a next CCA location at a next frameboundary and to perform eCCA at the next CCA location.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowchart of FIG. 12. Assuch, each block in the aforementioned flowchart of FIG. 12 may beperformed by a component and the apparatus may include one or more ofthose components. The components may be one or more hardware componentsspecifically configured to carry out the stated processes/algorithm,implemented by a processor configured to perform the statedprocesses/algorithm, stored within a computer-readable medium forimplementation by a processor, or some combination thereof.

FIG. 14 is a diagram 1400 illustrating an example of a hardwareimplementation for an apparatus 1302′ employing a processing system1414. The processing system 1414 may be implemented with a busarchitecture, represented generally by the bus 1424. The bus 1424 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1414 and the overalldesign constraints. The bus 1424 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 1404, the components 1304, 1306, 1308, 1310, 1312,1314, 1316, 1318, and the computer-readable medium/memory 1406. The bus1424 may also link various other circuits such as timing sources,peripherals, voltage regulators, and power management circuits, whichare well known in the art, and therefore, will not be described anyfurther.

The processing system 1414 may be coupled to a transceiver 1410. Thetransceiver 1410 is coupled to one or more antennas 1420. Thetransceiver 1410 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1410 receives asignal from the one or more antennas 1420, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1414, specifically the reception component 1304. Inaddition, the transceiver 1410 receives information from the processingsystem 1414, specifically the transmission component 1306, and based onthe received information, generates a signal to be applied to the one ormore antennas 1420. The processing system 1414 includes a processor 1404coupled to a computer-readable medium/memory 1406. The processor 1404 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 1406. The software, whenexecuted by the processor 1404, causes the processing system 1414 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 1406 may also be used forstoring data that is manipulated by the processor 1404 when executingsoftware. The processing system 1414 further includes at least one ofthe components 1304, 1306, 1308, 1310, 1312, 1314, 1316, 1318. Thecomponents may be software components running in the processor 1404,resident/stored in the computer readable medium/memory 1406, one or morehardware components coupled to the processor 1404, or some combinationthereof. The processing system 1414 may be a component of the basestation 105 and may include the memory 642 and/or at least one of the TXprocessor 620, the RX processor 638, and the controller/processor 640.

In one configuration, the apparatus 1302/1302′ for wirelesscommunication includes means for performing a dual clear channelassessment (CCA) procedure for a frame, means for transmitting, meansfor refraining from transmitting, means for transmitting a reservationsignal when the CCA/eCCA is successful, and means for transmitting aframe transmission following the reservation signal. The aforementionedmeans may be one or more of the aforementioned components of theapparatus 1302 and/or the processing system 1414 of the apparatus 1302′configured to perform the functions recited by the aforementioned means.As described supra, the processing system 1414 may include the TXProcessor 620, the RX Processor 638, and the controller/processor 640.As such, in one configuration, the aforementioned means may be the TXProcessor 620, the RX Processor 638, and the controller/processor 640configured to perform the functions recited by the aforementioned means.

FIG. 15 is a flowchart 1500 of a method of wireless communication. Themethod may be performed by a UE (e.g., UE 115, 115-a, 115-b, 1350, theapparatus 1602, 1602′) communicating wirelessly with a base station(e.g., base station 105, 105-a, 105-b, the apparatus 1302/1302′). Thewireless communication may comprise eMTC. Optional aspects of the methodare illustrated with a dashed line. At 1508, the UE segments an uplinkduration in each frame into multiple transmission units for eachfrequency, where a frame comprises an integer number of the transmissionunits, e.g., as described in connection with FIG. 10.

At 1510, the UE transmits uplink communication based on the multipletransmission units, where each transmission unit comprises at least oneon period and at least one off period corresponding to each of aplurality of frequencies, wherein during an on period the UE transmitsuplink communication on the corresponding frequency and during an offperiod the UE refrains from transmitting uplink communication on thecorresponding frequency.

In one example, each transmission unit may comprise multiple on periodsand multiple off periods. The on period(s) and the off period(s) may beconfigured by a base station for each frame type. Thus, the UE mayreceive a configuration of on period(s)/off period(s) from the basestation at 1502. In another example, the on period(s) and the offperiod(s) may be specified for each frame type.

In one example, each on period may be smaller than each off period. Inanother example, each on period may have a same length as each offperiod. For example, each on period may comprise a length of 5 ms andeach off period may comprise a length of 5 ms.

The transmission units of the UE may be multiplexed with secondtransmission units of a second UE, wherein the on period of thetransmission units of the UE corresponds to a second off period for thesecond transmission units of the second UE and the off period of thetransmission units of the UE correspond to a second on period for thesecond transmission units of the second UE, e.g., as described inconnection with FIG. 10. As described in connection with FIG. 10, anuplink duration in each frame may be divided into multiple transmissionperiods. While FIG. 10 illustrates an example with two periods,different numbers of transmission periods may be provided within theuplink duration. Thus, in an example with three UEs, there may be threeperiods, and each UE may have one on period and the two remainingperiods as an off period. The on periods for the UEs may be interleavedfor constant use of the spectrum. In an example with four UEs, each UEmay be configured with a single on period followed by three off periods,in order to enable the on periods for the four UEs to be interleavedwith each other.

The UE may transmit the communication at 1510 without performing an LBTprocedure. In another example, the UE may transmit the uplinkcommunication at 1510 subject to an LBT procedure in each transmissionunit. In yet another example, the UE may transmit the uplinkcommunication at 1510 subject to an LBT procedure in each on period.

The UE may receive, at 1504, uplink scheduling from a base station inscheduling units based on the transmission units. The uplinkcommunication may be transmitted at 1510 based on the received uplinkscheduling at 1504.

The UE may receive, at 1506, an uplink start delay in scheduling unitsbased on the transmission units. The uplink communication may betransmitted at 1510 based on the received uplink start delay at 1506.

DMRS transmissions and PUSCH transmissions within a same transmissionunit may be based on a same RV and a same scrambling sequence.

FIG. 16 is a conceptual data flow diagram 1600 illustrating the dataflow between different means/components in an example apparatus 1602.The apparatus may be a UE (e.g., UE 115, 115-a, 115-b, 1350). Theapparatus includes a reception component 1604 that receives downlinkcommunication 1601 from a base station 1650 (e.g., base station 105,105-a, 105-b, the apparatus 1302/1302′) and a transmission component1606 that transmits uplink communication 1603 to base station 1650. Thewireless communication may comprise eMTC. The apparatus may include asegmentation component 1610 configured to segment an uplink duration ineach frame into multiple transmission units for each frequency, whereina frame comprises an integer number of the transmission units. The onperiod and the off period may be configured by a base station orspecified for each frame type. Therefore, the apparatus may include aconfiguration component 1608 configured to receive a configuration ofthe on/off period(s) from the base station 1650. The transmissioncomponent 1606 may be configured to transmit uplink communication basedon the multiple transmission units, wherein each transmission unitcomprises at least one on period and at least one off periodcorresponding to each of a plurality of frequencies, wherein during anon period the UE transmits uplink communication on the correspondingfrequency and during an off period the UE refrains from transmittinguplink communication on the corresponding frequency. The apparatus mayinclude an uplink schedule component 1612 configured to receive uplinkscheduling from a base station in scheduling units based on thetransmission units. The transmission component 1606 may transmit uplinkcommunication based on the received uplink scheduling. The apparatus mayinclude a transmission delay component 1614 configured to receive anuplink start delay in scheduling units based on the transmission units.The transmission component 1606 may delay the uplink transmission basedon the received uplink start delay.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowchart of FIG. 15. Assuch, each block in the aforementioned flowchart of FIG. 15 may beperformed by a component and the apparatus may include one or more ofthose components. The components may be one or more hardware componentsspecifically configured to carry out the stated processes/algorithm,implemented by a processor configured to perform the statedprocesses/algorithm, stored within a computer-readable medium forimplementation by a processor, or some combination thereof.

FIG. 17 is a diagram 1700 illustrating an example of a hardwareimplementation for an apparatus 1602′ employing a processing system1714. The processing system 1714 may be implemented with a busarchitecture, represented generally by the bus 1724. The bus 1724 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1714 and the overalldesign constraints. The bus 1724 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 1704, the components 1604, 1606, 1608, 1610, 1612,1614, and the computer-readable medium/memory 1706. The bus 1724 mayalso link various other circuits such as timing sources, peripherals,voltage regulators, and power management circuits, which are well knownin the art, and therefore, will not be described any further.

The processing system 1714 may be coupled to a transceiver 1710. Thetransceiver 1710 is coupled to one or more antennas 1720. Thetransceiver 1710 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1710 receives asignal from the one or more antennas 1720, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1714, specifically the reception component 1604. Inaddition, the transceiver 1710 receives information from the processingsystem 1714, specifically the transmission component 1606, and based onthe received information, generates a signal to be applied to the one ormore antennas 1720. The processing system 1714 includes a processor 1704coupled to a computer-readable medium/memory 1706. The processor 1704 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 1706. The software, whenexecuted by the processor 1704, causes the processing system 1714 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 1706 may also be used forstoring data that is manipulated by the processor 1704 when executingsoftware. The processing system 1714 further includes at least one ofthe components 1604, 1606, 1608, 1610, 1612, 1614. The components may besoftware components running in the processor 1704, resident/stored inthe computer readable medium/memory 1706, one or more hardwarecomponents coupled to the processor 1704, or some combination thereof.The processing system 1714 may be a component of the UE 115 and mayinclude the memory 682 and/or at least one of the TX processor 664, theRX processor 658, and the controller/processor 680.

In one configuration, the apparatus 1602/1602′ for wirelesscommunication includes means for segmenting an uplink duration in eachframe into multiple transmission units for each frequency, wherein aframe comprises an integer number of the transmission units, means fortransmitting uplink communication based on the multiple transmissionunits, wherein each transmission unit comprises at least one on periodand at least one off period corresponding to each of a plurality offrequencies, wherein during an on period the UE transmits uplinkcommunication on the corresponding frequency and during an off periodthe UE refrains from transmitting uplink communication on thecorresponding frequency, means for receiving on/off period configurationfrom a base station, means for receiving uplink scheduling from a basestation in scheduling units based on the transmission units, and meansfor receiving an uplink start delay in scheduling units based on thetransmission units.

The processing system 1714 may be a component of the UE 115 and mayinclude the memory 682 and/or at least one of the TX processor 664, theRX processor 658, and the controller/processor 680.

The aforementioned means may be one or more of the aforementionedcomponents of the apparatus 1602 and/or the processing system 1714 ofthe apparatus 1602′ configured to perform the functions recited by theaforementioned means. As described supra, the processing system 1714 mayinclude the TX Processor 664, the RX Processor 658, and thecontroller/processor 680. As such, in one configuration, theaforementioned means may be the TX Processor 664, the RX Processor 658,and the controller/processor 680 configured to perform the functionsrecited by the aforementioned means.

FIG. 18 is a flowchart 1800 of a method of wireless communication. Thewireless communication may comprise IoT communication, e.g., eMTC,NB-IoT, etc. The method may be performed by a UE (e.g., UE 115, 115-a,115-b, 2250, the apparatus 1902, 1902′) configured for wirelesscommunication with a base station e.g., base station 105, 105-a, 105-b,1950, the apparatus 2202/2202′). At 1802, the UE transmits uplinktransmissions in a plurality of transmission units. The user equipmentmay transmit the uplink transmissions without performing an LBTprocedure at a beginning of a frame.

At 1804, the UE hops frequency bands in a first pattern across framesbased on a base station hopping pattern, e.g., as described inconnection with FIG. 11. The first pattern may comprise a fixed pattern.

The uplink transmissions may be transmitted based on dual hoppingpatterns, e.g., as described in connection with FIG. 11. Therefore, at1806, the UE may also hop frequency in a second pattern acrosstransmission units within the base station's channel occupancy within aframe. The base station's channel occupancy may comprise a narrowbandwithin a designated frequency band. The user equipment transmits theuplink transmissions in a same narrowband within the correspondingchannel occupancy of the base station in each frame. An uplinknarrowband and a downlink narrowband for the wireless communication maybe different.

Thus, in transmitting the uplink transmission at 1802, the userequipment may hop based on 1804 and 1806.

The user equipment may transmit up to a maximum number of transmissionunits per frequency before hopping frequency bands. The maximum numbermay be based on a number of downlink subframes in a frame structure anda number of narrowbands on which the user equipment can hop.

FIG. 19 is a conceptual data flow diagram 1900 illustrating the dataflow between different means/components in an example apparatus 1902.The apparatus may be a UE (e.g., UE 115, 115-a, 115-b, 2250). Theapparatus includes a reception component 1904 that receives downlinkcommunication 1901 from a base station 1950 (e.g., base station 105,105-a, 105-b, the apparatus 2202/2202′) and a transmission component1906 that transmits uplink communication 1903 to base station 1950. Thewireless communication may comprise IoT communication, e.g., eMTC,NB-IoT, etc. The apparatus may comprise a transmission unit component1908 configured to transmit uplink transmissions in a plurality oftransmission units and a first hopping pattern component 1910 configuredto hop frequency bands in a first pattern across frames based on a basestation hopping pattern. The apparatus may also include a second hoppingpattern component 1912 configured to hop in a second pattern acrosstransmission units within the base station's channel occupancy within aframe, wherein the uplink transmissions are transmitted based on dualhopping patterns.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowchart of FIG. 18. Assuch, each block in the aforementioned flowchart of FIG. 18 may beperformed by a component and the apparatus may include one or more ofthose components. The components may be one or more hardware componentsspecifically configured to carry out the stated processes/algorithm,implemented by a processor configured to perform the statedprocesses/algorithm, stored within a computer-readable medium forimplementation by a processor, or some combination thereof.

FIG. 20 is a diagram 2000 illustrating an example of a hardwareimplementation for an apparatus 1902′ employing a processing system2014. The processing system 2014 may be implemented with a busarchitecture, represented generally by the bus 2024. The bus 2024 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 2014 and the overalldesign constraints. The bus 2024 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 2004, the components 1904, 1906, 1908, 1910, 1912, andthe computer-readable medium/memory 2006. The bus 2024 may also linkvarious other circuits such as timing sources, peripherals, voltageregulators, and power management circuits, which are well known in theart, and therefore, will not be described any further.

The processing system 2014 may be coupled to a transceiver 2010. Thetransceiver 2010 is coupled to one or more antennas 2020. Thetransceiver 2010 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 2010 receives asignal from the one or more antennas 2020, extracts information from thereceived signal, and provides the extracted information to theprocessing system 2014, specifically the reception component 1904. Inaddition, the transceiver 2010 receives information from the processingsystem 2014, specifically the transmission component 1906, and based onthe received information, generates a signal to be applied to the one ormore antennas 2020. The processing system 2014 includes a processor 2004coupled to a computer-readable medium/memory 2006. The processor 2004 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 2006. The software, whenexecuted by the processor 2004, causes the processing system 2014 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 2006 may also be used forstoring data that is manipulated by the processor 2004 when executingsoftware. The processing system 2014 further includes at least one ofthe components 1904, 1906, 1908, 1910, 1912. The components may besoftware components running in the processor 2004, resident/stored inthe computer readable medium/memory 2006, one or more hardwarecomponents coupled to the processor 2004, or some combination thereof.The processing system 2014 may be a component of the UE 115 and mayinclude the memory 682 and/or at least one of the TX processor 664, theRX processor 658, and the controller/processor 680.

In one configuration, the apparatus 1902/1902′ for wirelesscommunication includes means for transmitting uplink transmissions in aplurality of transmission units, means for hopping frequency bands in afirst pattern across frames based on a base station hopping pattern, andmeans for hopping in a second pattern across transmission units withinthe base station's channel occupancy within a frame.

The aforementioned means may be one or more of the aforementionedcomponents of the apparatus 1902 and/or the processing system 2014 ofthe apparatus 1902′ configured to perform the functions recited by theaforementioned means. As described supra, the processing system 2014 mayinclude the TX Processor 664, the RX Processor 658, and thecontroller/processor 680. As such, in one configuration, theaforementioned means may be the TX Processor 664, the RX Processor 658,and the controller/processor 680 configured to perform the functionsrecited by the aforementioned means.

FIG. 21 is a flowchart 2100 of a method of wireless communication. Thewireless communication may comprise IoT communication, e.g., eMTC,NB-IoT, etc. The method may be performed by a base station (e.g., basestation 105, 105-a, 105-b, 1950, the apparatus 2202/2202′) configured tocommunicate wirelessly with a UE (e.g., UE 115, 115-a, 115-b, 2250, theapparatus 1902, 1902′). At 2102, the base station hops frequency bandsin a first pattern across frames based on a base station hoppingpattern, e.g., as described in connection with FIG. 11. At 2104, thebase station receives uplink transmissions in a narrowband from a UE ina plurality of transmission units within the frequency bands based onthe base station hopping pattern. The uplink transmission may bereceived from the user equipment based on dual hopping patterns, whereinthe UE hops in a second pattern across transmission units within thebase station's channel occupancy within a frame. The uplink transmissionmay be received from the user equipment in the same narrowband withinthe corresponding channel occupancy of the base station in each frame.

The base station may comprise a wideband base station. Therefore, thebase station may multiplex communication with a plurality of narrowbandUEs at 2106.

The uplink transmission may be received in an uplink narrowband, and thebase station may transmit downlink communication to the user equipmentin a downlink narrowband, wherein the uplink narrowband is differentthan the downlink narrowband at 2108.

The base station may hop frequency channels in the first pattern acrossframes in coordination with at least one neighbor base station to occupydifferent frequency channels than the at least one neighbor basestation. The hopping may be performed across a number of frequencychannels, the number being based on a bandwidth used by the basestation. The number may be further based on based on a minimum number offrequencies required by the user equipment.

FIG. 22 is a conceptual data flow diagram 2200 illustrating the dataflow between different means/components in an example apparatus 2202.The apparatus may be a base station (e.g., base station 105, 105-a,105-b, 1950). The apparatus includes a reception component 2204 thatreceives UL communication from a UE (e.g., UE 115, 115-a, 115-b, 2250,the apparatus 1902, 1902′) and a transmission component 2206 thattransmits downlink communication to the UE 2250. The wirelesscommunication may comprise IoT communication, e.g., eMTC, NB-IoT, etc.The apparatus may include a hopping component 2208 configured to hopfrequency bands in a first pattern across frames based on a base stationhopping pattern. The reception component 2204 may be configured toreceive uplink transmissions in a narrowband from a user UE in aplurality of transmission units within the frequency bands based on thebase station hopping pattern. The uplink transmission may be receivedfrom the user equipment based on dual hopping patterns, wherein the UEhops in a second pattern across transmission units within the basestation's channel occupancy within a frame. The uplink transmission maybe received from the user equipment in the same narrowband within thecorresponding channel occupancy of the base station in each frame.

The apparatus may comprise a wideband base station and may include amultiplex component 2210 configured to multiplex communication with aplurality of narrowband UEs.

The uplink transmission may be received in an uplink narrowband. Thetransmission component 2206 may be configured to transmit downlinkcommunication to the user equipment in a downlink narrowband, whereinthe uplink narrowband is different than the downlink narrowband.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowchart of FIG. 21. Assuch, each block in the aforementioned flowchart of FIG. 21 may beperformed by a component and the apparatus may include one or more ofthose components. The components may be one or more hardware componentsspecifically configured to carry out the stated processes/algorithm,implemented by a processor configured to perform the statedprocesses/algorithm, stored within a computer-readable medium forimplementation by a processor, or some combination thereof.

FIG. 23 is a diagram 2300 illustrating an example of a hardwareimplementation for an apparatus 2202′ employing a processing system2314. The processing system 2314 may be implemented with a busarchitecture, represented generally by the bus 2324. The bus 2324 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 2314 and the overalldesign constraints. The bus 2324 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 2304, the components 2204, 2206, 2208, 2210, and thecomputer-readable medium/memory 2306. The bus 2324 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore, will not be described any further.

The processing system 2314 may be coupled to a transceiver 2310. Thetransceiver 2310 is coupled to one or more antennas 2320. Thetransceiver 2310 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 2310 receives asignal from the one or more antennas 2320, extracts information from thereceived signal, and provides the extracted information to theprocessing system 2314, specifically the reception component 2204. Inaddition, the transceiver 2310 receives information from the processingsystem 2314, specifically the transmission component 2206, and based onthe received information, generates a signal to be applied to the one ormore antennas 2320. The processing system 2314 includes a processor 2304coupled to a computer-readable medium/memory 2306. The processor 2304 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 2306. The software, whenexecuted by the processor 2304, causes the processing system 2314 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 2306 may also be used forstoring data that is manipulated by the processor 2304 when executingsoftware. The processing system 2314 further includes at least one ofthe components 2204, 2206, 2208, 2210. The components may be softwarecomponents running in the processor 2304, resident/stored in thecomputer readable medium/memory 2306, one or more hardware componentscoupled to the processor 2304, or some combination thereof. Theprocessing system 2314 may be a component of the base station 105 andmay include the memory 642 and/or at least one of the TX processor 620,the RX processor 638, and the controller/processor 640.

In one configuration, the apparatus 2202/2202′ for wirelesscommunication includes means for means for hopping frequency bands in afirst pattern across frames based on a base station hopping pattern,means for receiving uplink transmissions in a narrowband from a userequipment (UE) in a plurality of transmission units within the frequencybands based on the base station hopping pattern, means for multiplexingcommunication with a plurality of narrowband UEs, and means fortransmitting downlink communication to the user equipment in a downlinknarrowband, wherein the uplink narrowband is different than the downlinknarrowband. The aforementioned means may be one or more of theaforementioned components of the apparatus 2202 and/or the processingsystem 2314 of the apparatus 2202′ configured to perform the functionsrecited by the aforementioned means. As described supra, the processingsystem 2314 may include the TX Processor 620, the RX Processor 638, andthe controller/processor 640. As such, in one configuration, theaforementioned means may be the TX Processor 620, the RX Processor 638,and the controller/processor 640 configured to perform the functionsrecited by the aforementioned means.

FIG. 24 is a flowchart 2400 of a method of wireless communication. Thewireless communication may comprise IoT communication, e.g., eMTC,NB-IoT, etc. The method may be performed by a base station (e.g., basestation 105, 105-a, 105-b, 2850, the apparatus 2502/2502′) configured tocommunicate wirelessly with a UE (e.g., UE 115, 115-a, 115-b, 2550, theapparatus 2802, 2802′). At 2402, the base station performs performing anLBT procedure at a beginning of each of a plurality of frames. At 2406,the base station transmits a plurality of repetitions of a transmission.The base station transmission may comprise a control channeltransmission, e.g., an MPDCCH transmission. The transmission maycomprise a data transmission, e.g., an MPDSCH transmission. When theplurality of repetitions span multiple frames and an LBT procedure isnot successful for a first frame, the base station drops at least onerepetition in the first frame or postpones the at least one repetitionin the first frame until a second frame when the LBT procedure issuccessful 2404.

At 2408, the base station may determine whether to drop the at least onerepetition or postpone the at least one repetition in a frame in whichthe LBT procedure is unsuccessful. The base station may drop the atleast one repetition in the first frame. The base station may postponethe at least one repetition in the first frame until the second framewhen the LBT procedure is successful. The determining at 2408 may bebased on at least one of an interference environment, a likelihood of auser equipment missing the transmission directed to the user equipment,a likelihood of the user equipment making a false detection, areliability of the user equipment detecting whether the base stationdrops or postpones the transmission, and user equipment procedures ofthe UE.

At 2410, the base station may receive at least one of an uplink controltransmission, an uplink data transmission, or a RACH transmission from auser equipment in the frame when the base station did not transmit adownlink transmission. The base station may receive the RACHtransmission from the user equipment, and wherein the RACH transmissionis based on an allocated cell specific configuration.

FIG. 25 is a conceptual data flow diagram 2500 illustrating the dataflow between different means/components in an example apparatus 2502.The apparatus may be a base station (e.g., base station 105, 105-a,105-b, 2850) configured to communicate wirelessly with a UE (e.g., UE115, 115-a, 115-b, 2550, the apparatus 2802, 2802′). The wirelesscommunication may comprise IoT communication, e.g., eMTC, NB-IoT, etc.The apparatus includes a reception component 2504 that receives uplinkcommunication from UE 2550 and a transmission component 2506 thattransmits downlink communication to UE 2250. The apparatus may includean LBT component 2508 configured to perform an LBT procedure at abeginning of each of a plurality of frames. The apparatus may include arepetition component 2510 configured to transmit a plurality ofrepetitions of a transmission, wherein when the plurality of repetitionsspan multiple frames. When the LBT procedure is not successful for afirst frame, the repetition component 2510 may drop at least onerepetition in the first frame or postpone the at least one repetition inthe first frame until a second frame when the LBT procedure issuccessful. The apparatus may include a drop/postpone component 2512configured to determine whether to drop the at least one repetition orpostpone the at least one repetition in a frame in which the LBTprocedure is unsuccessful. The apparatus may include an UL component2514 configured to receive at least one of an uplink controltransmission, an uplink data transmission, or a RACH transmission from auser equipment in the frame when the base station did not transmit adownlink transmission.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowchart of FIG. 24. Assuch, each block in the aforementioned flowcharts of FIG. 24 may beperformed by a component and the apparatus may include one or more ofthose components. The components may be one or more hardware componentsspecifically configured to carry out the stated processes/algorithm,implemented by a processor configured to perform the statedprocesses/algorithm, stored within a computer-readable medium forimplementation by a processor, or some combination thereof.

FIG. 26 is a diagram 2600 illustrating an example of a hardwareimplementation for an apparatus 2502′ employing a processing system2614. The processing system 2614 may be implemented with a busarchitecture, represented generally by the bus 2624. The bus 2624 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 2614 and the overalldesign constraints. The bus 2624 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 2604, the components 2504, 2506, 2508, 2510, 2512, andthe computer-readable medium/memory 2606. The bus 2624 may also linkvarious other circuits such as timing sources, peripherals, voltageregulators, and power management circuits, which are well known in theart, and therefore, will not be described any further.

The processing system 2614 may be coupled to a transceiver 2610. Thetransceiver 2610 is coupled to one or more antennas 2620. Thetransceiver 2610 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 2610 receives asignal from the one or more antennas 2620, extracts information from thereceived signal, and provides the extracted information to theprocessing system 2614, specifically the reception component 2504. Inaddition, the transceiver 2610 receives information from the processingsystem 2614, specifically the transmission component 2506, and based onthe received information, generates a signal to be applied to the one ormore antennas 2620. The processing system 2614 includes a processor 2604coupled to a computer-readable medium/memory 2606. The processor 2604 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 2606. The software, whenexecuted by the processor 2604, causes the processing system 2614 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 2606 may also be used forstoring data that is manipulated by the processor 2604 when executingsoftware. The processing system 2614 further includes at least one ofthe components 2504, 2506, 2508, 2510, 2512. The components may besoftware components running in the processor 2604, resident/stored inthe computer readable medium/memory 2606, one or more hardwarecomponents coupled to the processor 2604, or some combination thereof.The processing system 2614 may be a component of the base station 105and may include the memory 642 and/or at least one of the TX processor620, the RX processor 638, and the controller/processor 640.

In one configuration, the apparatus 2502/2502′ for wirelesscommunication includes means for performing an LBT procedure at abeginning of each of a plurality of frames, means for transmitting aplurality of repetitions of a transmission, wherein when the pluralityof repetitions span multiple frames and the LBT procedure is notsuccessful for a first frame, the base station drops at least onerepetition in the first frame or postpones the at least one repetitionin the first frame until a second frame when the LBT procedure issuccessful, means for determining whether to drop the at least onerepetition or postpone the at least one repetition in a frame in whichthe LBT procedure is unsuccessful, and means for receiving at least oneof an uplink control transmission, an uplink data transmission, or aRACH transmission from a user equipment in the frame when the basestation did not transmit a downlink transmission.

The aforementioned means may be one or more of the aforementionedcomponents of the apparatus 2502 and/or the processing system 2614 ofthe apparatus 2502′ configured to perform the functions recited by theaforementioned means. As described supra, the processing system 2614 mayinclude the TX Processor 620, the RX Processor 638, and thecontroller/processor 640. As such, in one configuration, theaforementioned means may be the TX Processor 620, the RX Processor 638,and the controller/processor 640 configured to perform the functionsrecited by the aforementioned means.

FIG. 27 is a flowchart 2700 of a method of wireless communication. Thewireless communication may comprise IoT communication, e.g., eMTC,NB-IoT, etc. The method may be performed by a UE (e.g., UE 115, 115-a,115-b, 2550, the apparatus 2802, 2802′) configured to communicatewirelessly with a base station (e.g., base station 105, 105-a, 105-b,2850, the apparatus 2502/2502′). At 2702, the UE receives a plurality ofrepetitions of a downlink transmission from a base station. Thetransmission may comprise a control channel transmission, e.g., MPDCCH.The transmission may comprise a data transmission, e.g., MPDSCH.

When the plurality of repetitions span multiple frames, the UEdetermines at 2704 whether the base station transmits at least onerepetition of the downlink transmission in a first frame. Thedetermining may include determining whether the base station drops theat least one repetition in the first frame or postpones the at least onerepetition in the first frame until a second frame.

At 2706, the UE may combine the plurality of repetitions across themultiple frames.

At 2708, the UE transmits at least one of an uplink controltransmission, an uplink data transmission, or a RACH transmission from auser equipment in the frame when the base station did not transmit adownlink transmission. The user equipment may transmit a RACHtransmission at 2708 to the base station in the frame when the basestation did not transmit the downlink transmission, and the RACHtransmission may be based on an allocated cell specific configuration.

FIG. 28 is a conceptual data flow diagram 2800 illustrating the dataflow between different means/components in an example apparatus 2802.The apparatus may be a UE (e.g., UE 115, 115-a, 115-b, 2550) configuredto communicate wirelessly with a base station (e.g., base station 105,105-a, 105-b, 2850, the apparatus 2502/2502′). The wirelesscommunication may comprise IoT communication, e.g., eMTC, NB-IoT, etc.The apparatus includes a reception component 2804 that receives downlinkcommunication from base station 2850 and an transmission component thattransmits uplink communication to base station 2850.

The reception component 2804 may be configured to receive a plurality ofrepetitions of a downlink transmission from a base station. Theapparatus may include a determination component 2808 configured todetermine whether the base station transmits at least one repetition ofthe downlink transmission in a first frame. The determining may includedetermining whether the base station drops the at least one repetitionin the first frame or postpones the at least one repetition in the firstframe until a second frame. The apparatus may include a combinationcomponent 2810 configured to combine the plurality of repetitions acrossthe multiple frames. The apparatus may include an UL component 2814and/or a RACH component 1812 configured to transmit at least one of anuplink control transmission, an uplink data transmission, or a RACHtransmission from a user equipment in the frame when the base stationdid not transmit a downlink transmission.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowchart of FIG. 27. Assuch, each block in the aforementioned flowchart of FIG. 27 may beperformed by a component and the apparatus may include one or more ofthose components. The components may be one or more hardware componentsspecifically configured to carry out the stated processes/algorithm,implemented by a processor configured to perform the statedprocesses/algorithm, stored within a computer-readable medium forimplementation by a processor, or some combination thereof.

FIG. 29 is a diagram 2900 illustrating an example of a hardwareimplementation for an apparatus 2802′ employing a processing system2914. The processing system 2914 may be implemented with a busarchitecture, represented generally by the bus 2924. The bus 2924 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 2914 and the overalldesign constraints. The bus 2924 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 2904, the components 2804, 2806, 2808, 2810, 2812,2814, and the computer-readable medium/memory 2906. The bus 2924 mayalso link various other circuits such as timing sources, peripherals,voltage regulators, and power management circuits, which are well knownin the art, and therefore, will not be described any further.

The processing system 2914 may be coupled to a transceiver 2910. Thetransceiver 2910 is coupled to one or more antennas 2920. Thetransceiver 2910 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 2910 receives asignal from the one or more antennas 2920, extracts information from thereceived signal, and provides the extracted information to theprocessing system 2914, specifically the reception component 2804. Inaddition, the transceiver 2910 receives information from the processingsystem 2914, specifically the transmission component 2806, and based onthe received information, generates a signal to be applied to the one ormore antennas 2920. The processing system 2914 includes a processor 2904coupled to a computer-readable medium/memory 2906. The processor 2904 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 2906. The software, whenexecuted by the processor 2904, causes the processing system 2914 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 2906 may also be used forstoring data that is manipulated by the processor 2904 when executingsoftware. The processing system 2914 further includes at least one ofthe components 2804, 2806, 2808, 2810, 2812, 2814. The components may besoftware components running in the processor 2904, resident/stored inthe computer readable medium/memory 2906, one or more hardwarecomponents coupled to the processor 2904, or some combination thereof.The processing system 2914 may be a component of the UE 115 and mayinclude the memory 682 and/or at least one of the TX processor 664, theRX processor 658, and the controller/processor 680.

In one configuration, the apparatus 2802/2802′ for wirelesscommunication includes means for receiving a plurality of repetitions ofa downlink transmission from a base station, means for determiningwhether the base station transmits at least one repetition of thedownlink transmission in a first frame, means for combining theplurality of repetitions across the multiple frames, and means fortransmitting at least one of an uplink control transmission, an uplinkdata transmission, or a RACH transmission from a user equipment in theframe when the base station did not transmit a downlink transmission.

The aforementioned means may be one or more of the aforementionedcomponents of the apparatus 2802 and/or the processing system 2914 ofthe apparatus 2802′ configured to perform the functions recited by theaforementioned means. As described supra, the processing system 2914 mayinclude the TX Processor 664, the RX Processor 658, and thecontroller/processor 680. As such, in one configuration, theaforementioned means may be the TX Processor 664, the RX Processor 658,and the controller/processor 680 configured to perform the functionsrecited by the aforementioned means.

It is understood that the specific order or hierarchy of blocks in theprocesses/flowcharts disclosed is an illustration of example approaches.Based upon design preferences, it is understood that the specific orderor hierarchy of blocks in the processes/flowcharts may be rearranged.Further, some blocks may be combined or omitted. The accompanying methodclaims present elements of the various blocks in a sample order, and arenot meant to be limited to the specific order or hierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects. Unless specifically statedotherwise, the term “some” refers to one or more. Combinations such as“at least one of A, B, or C,” “one or more of A, B, or C,” “at least oneof A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or anycombination thereof” include any combination of A, B, and/or C, and mayinclude multiples of A, multiples of B, or multiples of C. Specifically,combinations such as “at least one of A, B, or C,” “one or more of A, B,or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and“A, B, C, or any combination thereof” may be A only, B only, C only, Aand B, A and C, B and C, or A and B and C, where any such combinationsmay contain one or more member or members of A, B, or C. All structuraland functional equivalents to the elements of the various aspectsdescribed throughout this disclosure that are known or later come to beknown to those of ordinary skill in the art are expressly incorporatedherein by reference and are intended to be encompassed by the claims.Moreover, nothing disclosed herein is intended to be dedicated to thepublic regardless of whether such disclosure is explicitly recited inthe claims. The words “module,” “mechanism,” “element,” “device,” andthe like may not be a substitute for the word “means.” As such, no claimelement is to be construed as a means plus function unless the elementis expressly recited using the phrase “means for.”

What is claimed is:
 1. A method of wireless communication at a basestation, comprising: performing a Listen-Before-Talk (LBT) procedure ata beginning of each of a plurality of frames; and transmitting aplurality of repetitions of a transmission, wherein when the pluralityof repetitions span multiple frames and the LBT procedure is notsuccessful for a first frame, the base station drops at least onerepetition in the first frame or postpones the at least one repetitionin the first frame until a second frame when the LBT procedure issuccessful.
 2. The method of claim 1, wherein the transmission comprisesa control channel transmission.
 3. The method of claim 2, wherein thetransmission comprises a Machine Type Communication Physical DownlinkControl Channel (MPDCCH) transmission.
 4. The method of claim 1, whereinthe transmission comprises a data transmission.
 5. The method of claim4, wherein the transmission comprises a Machine Type CommunicationPhysical Downlink Shared Channel (MPDSCH) transmission.
 6. The method ofclaim 1, wherein the base station drops the at least one repetition inthe first frame.
 7. The method of claim 1, wherein the base stationpostpones the at least one repetition in the first frame until thesecond frame when the LBT procedure is successful.
 8. The method ofclaim 1, further comprising: determining whether to drop the at leastone repetition or postpone the at least one repetition in a frame inwhich the LBT procedure is unsuccessful.
 9. The method of claim 8,wherein the determining is based on at least one of: an interferenceenvironment; a likelihood of a user equipment missing the transmissiondirected to the user equipment; a likelihood of the user equipmentmaking a false detection; a reliability of the user equipment detectingwhether the base station drops or postpones the transmission; and userequipment procedures of the UE.
 10. The method of claim 1, furthercomprising: receiving at least one of an uplink control transmission, anuplink data transmission, or a Random Access Channel (RACH) transmissionfrom a user equipment in the frame when the base station did nottransmit a downlink transmission.
 11. The method of claim 10, whereinthe base station receives the RACH transmission from the user equipment,and wherein the RACH transmission is based on an allocated cell specificconfiguration.
 12. The method of claim 1, wherein the wirelesscommunication comprises Internet of Things (IoT) communication.
 13. Anapparatus for wireless communication at a base station, comprising:means for performing a Listen-Before-Talk (LBT) procedure at a beginningof each of a plurality of frames; and means for transmitting a pluralityof repetitions of a transmission, wherein when the plurality ofrepetitions span multiple frames and the LBT procedure is not successfulfor a first frame, the base station drops at least one repetition in thefirst frame or postpones the at least one repetition in the first frameuntil a second frame when the LBT procedure is successful.
 14. Theapparatus of claim 13, further comprising: means for determining whetherto drop the at least one repetition or postpone the at least onerepetition in a frame in which the LBT procedure is unsuccessful. 15.The apparatus of claim 14, wherein the determining is based on at leastone of: an interference environment; a likelihood of a user equipmentmissing the transmission directed to the user equipment; a likelihood ofthe user equipment making a false detection; a reliability of the userequipment detecting whether the base station drops or postpones thetransmission; and user equipment procedures of the UE.
 16. The apparatusof claim 13, further comprising: means for receiving at least one of anuplink control transmission, an uplink data transmission, or a RandomAccess Channel (RACH) transmission from a user equipment in the framewhen the base station did not transmit a downlink transmission.
 17. Theapparatus of claim 16, wherein the base station receives the RACHtransmission from the user equipment, and wherein the RACH transmissionis based on an allocated cell specific configuration.
 18. An apparatusfor wireless communication at a base station, comprising: a memory; andat least one processor coupled to the memory and configured to: performa Listen-Before-Talk (LBT) procedure at a beginning of each of aplurality of frames; and transmit a plurality of repetitions of atransmission, wherein when the plurality of repetitions span multipleframes and the LBT procedure is not successful for a first frame, thebase station drops at least one repetition in the first frame orpostpones the at least one repetition in the first frame until a secondframe when the LBT procedure is successful.
 19. The apparatus of claim18, wherein the at least one processor is further configured to:determine whether to drop the at least one repetition or postpone the atleast one repetition in a frame in which the LBT procedure isunsuccessful.
 20. The apparatus of claim 19, wherein the determining isbased on at least one of: an interference environment; a likelihood of auser equipment missing the transmission directed to the user equipment;a likelihood of the user equipment making a false detection; areliability of the user equipment detecting whether the base stationdrops or postpones the transmission; and user equipment procedures ofthe UE.
 21. The apparatus of claim 18, wherein the at least oneprocessor is further configured to: receive at least one of an uplinkcontrol transmission, an uplink data transmission, or a Random AccessChannel (RACH) transmission from a user equipment in the frame when thebase station did not transmit a downlink transmission.
 22. The apparatusof claim 21, wherein the base station receives the RACH transmissionfrom the user equipment, and wherein the RACH transmission is based onan allocated cell specific configuration.
 23. A computer-readable mediumstoring computer executable code for wireless communication at a basestation, comprising code to: perform a Listen-Before-Talk (LBT)procedure at a beginning of each of a plurality of frames; and transmita plurality of repetitions of a transmission, wherein when the pluralityof repetitions span multiple frames and the LBT procedure is notsuccessful for a first frame, the base station drops at least onerepetition in the first frame or postpones the at least one repetitionin the first frame until a second frame when the LBT procedure issuccessful.
 24. The computer-readable medium of claim 23, furthercomprising code to: determine whether to drop the at least onerepetition or postpone the at least one repetition in a frame in whichthe LBT procedure is unsuccessful.
 25. The computer-readable medium ofclaim 24, wherein the determining is based on at least one of: aninterference environment; a likelihood of a user equipment missing thetransmission directed to the user equipment; a likelihood of the userequipment making a false detection; a reliability of the user equipmentdetecting whether the base station drops or postpones the transmission;and user equipment procedures of the UE.
 26. The computer-readablemedium of claim 23, further comprising code to: means for receiving atleast one of an uplink control transmission, an uplink datatransmission, or a Random Access Channel (RACH) transmission from a userequipment in the frame when the base station did not transmit a downlinktransmission.
 27. The computer-readable medium of claim 26, wherein thebase station receives the RACH transmission from the user equipment, andwherein the RACH transmission is based on an allocated cell specificconfiguration.
 28. A method of wireless communication at a base userequipment, comprising: receiving a plurality of repetitions of adownlink transmission from a base station; and when the plurality ofrepetitions span multiple frames, determining whether the base stationtransmits at least one repetition of the downlink transmission in afirst frame.
 29. The method of claim 28, wherein the determiningincludes determining whether the base station drops the at least onerepetition in the first frame or postpones the at least one repetitionin the first frame until a second frame.
 30. The method of claim 28,further comprising: combining the plurality of repetitions across themultiple frames.
 31. The method of claim 28, wherein the transmissioncomprises a control channel transmission.
 32. The method of claim 31,wherein the transmission comprises a Machine Type Communication PhysicalDownlink Control Channel (MPDCCH) transmission.
 33. The method of claim28, wherein the transmission comprises a data transmission.
 34. Themethod of claim 33, wherein the transmission comprises a Machine TypeCommunication Physical Downlink Shared Channel (MPDSCH) transmission.35. The method of claim 28, further comprising: transmitting at leastone of an uplink control transmission, an uplink data transmission, or aRandom Access Channel (RACH) transmission from a user equipment in theframe when the base station did not transmit a downlink transmission.36. The method of claim 35, wherein the user equipment transmits theRACH transmission to the base station in the frame when the base stationdid not transmit the downlink transmission, and wherein the RACHtransmission is based on an allocated cell specific configuration. 37.The method of claim 28, wherein the wireless communication comprisesInternet of Things (IoT) communication.
 38. An apparatus for wirelesscommunication at a user equipment, comprising: means for receiving aplurality of repetitions of a downlink transmission from a base station;and means for determining whether the base station transmits at leastone repetition of the downlink transmission in a first frame, when theplurality of repetitions span multiple frames.
 39. The apparatus ofclaim 38, wherein the determining includes determining whether the basestation drops the at least one repetition in the first frame orpostpones the at least one repetition in the first frame until a secondframe.
 40. The apparatus of claim 38, further comprising: means forcombining the plurality of repetitions across the multiple frames. 41.The apparatus of claim 38, further comprising: means for transmitting atleast one of an uplink control transmission, an uplink datatransmission, or a Random Access Channel (RACH) transmission from a userequipment in the frame when the base station did not transmit a downlinktransmission.
 42. The apparatus of claim 41, wherein the user equipmenttransmits the RACH transmission to the base station in the frame whenthe base station did not transmit the downlink transmission, and whereinthe RACH transmission is based on an allocated cell specificconfiguration.
 43. An apparatus for wireless communication at a userequipment, comprising: a memory; and at least one processor coupled tothe memory and configured to: receive a plurality of repetitions of adownlink transmission from a base station; and determine whether thebase station transmits at least one repetition of the downlinktransmission in a first frame, when the plurality of repetitions spanmultiple frames.
 44. The apparatus of claim 43, wherein the determiningincludes determining whether the base station drops the at least onerepetition in the first frame or postpones the at least one repetitionin the first frame until a second frame.
 45. The apparatus of claim 43,wherein the at least one processor is further configured to: combine theplurality of repetitions across the multiple frames.
 46. The apparatusof claim 43, wherein the at least one processor is further configuredto: transmit at least one of an uplink control transmission, an uplinkdata transmission, or a Random Access Channel (RACH) transmission from auser equipment in the frame when the base station did not transmit adownlink transmission.
 47. The apparatus of claim 46, wherein the userequipment transmits the RACH transmission to the base station in theframe when the base station did not transmit the downlink transmission,and wherein the RACH transmission is based on an allocated cell specificconfiguration.
 48. A computer-readable medium storing computerexecutable code for wireless communication at a user equipment,comprising code to: receive a plurality of repetitions of a downlinktransmission from a base station; and determine whether the base stationtransmits at least one repetition of the downlink transmission in afirst frame, when the plurality of repetitions span multiple frames. 49.The computer-readable medium of claim 48, wherein the determiningincludes determining whether the base station drops the at least onerepetition in the first frame or postpones the at least one repetitionin the first frame until a second frame.
 50. The computer-readablemedium of claim 48, further comprising code to: combine the plurality ofrepetitions across the multiple frames.
 51. The computer-readable mediumof claim 48, further comprising code to: transmit at least one of anuplink control transmission, an uplink data transmission, or a RandomAccess Channel (RACH) transmission from a user equipment in the framewhen the base station did not transmit a downlink transmission.
 52. Thecomputer-readable medium of claim 51, wherein the user equipmenttransmits the RACH transmission to the base station in the frame whenthe base station did not transmit the downlink transmission, and whereinthe RACH transmission is based on an allocated cell specificconfiguration.